diff --git a/OpenSim/Framework/DoubleDictionaryThreadAbortSafe.cs b/OpenSim/Framework/DoubleDictionaryThreadAbortSafe.cs
new file mode 100644
index 0000000000..9056548a51
--- /dev/null
+++ b/OpenSim/Framework/DoubleDictionaryThreadAbortSafe.cs
@@ -0,0 +1,508 @@
+/*
+ * Copyright (c) 2008, openmetaverse.org, http://opensimulator.org/
+ * All rights reserved.
+ *
+ * - Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ * - Neither the name of the openmetaverse.org nor the names
+ *   of its contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Threading;
+using System.Collections.Generic;
+
+namespace OpenSim.Framework
+{
+    /// <summary>
+    /// A double dictionary that is thread abort safe.
+    /// </summary>
+    /// <remarks>
+    /// This adapts OpenMetaverse.DoubleDictionary to be thread-abort safe by acquiring ReaderWriterLockSlim within
+    /// a finally section (which can't be interrupted by Thread.Abort()).
+    /// </remarks>
+    public class DoubleDictionaryThreadAbortSafe<TKey1, TKey2, TValue>
+    {
+        Dictionary<TKey1, TValue> Dictionary1;
+        Dictionary<TKey2, TValue> Dictionary2;
+        ReaderWriterLockSlim rwLock = new ReaderWriterLockSlim();
+
+        public DoubleDictionaryThreadAbortSafe()
+        {
+            Dictionary1 = new Dictionary<TKey1,TValue>();
+            Dictionary2 = new Dictionary<TKey2,TValue>();
+        }
+
+        public DoubleDictionaryThreadAbortSafe(int capacity)
+        {
+            Dictionary1 = new Dictionary<TKey1, TValue>(capacity);
+            Dictionary2 = new Dictionary<TKey2, TValue>(capacity);
+        }
+
+        public void Add(TKey1 key1, TKey2 key2, TValue value)
+        {
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterWriteLock();
+                    gotLock = true;
+                }
+
+                if (Dictionary1.ContainsKey(key1))
+                {
+                    if (!Dictionary2.ContainsKey(key2))
+                        throw new ArgumentException("key1 exists in the dictionary but not key2");
+                }
+                else if (Dictionary2.ContainsKey(key2))
+                {
+                    if (!Dictionary1.ContainsKey(key1))
+                        throw new ArgumentException("key2 exists in the dictionary but not key1");
+                }
+
+                Dictionary1[key1] = value;
+                Dictionary2[key2] = value;
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitWriteLock(); 
+            }
+        }
+
+        public bool Remove(TKey1 key1, TKey2 key2)
+        {
+            bool success;
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterWriteLock();
+                    gotLock = true;
+                }
+
+                Dictionary1.Remove(key1);
+                success = Dictionary2.Remove(key2);
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitWriteLock(); 
+            }
+
+            return success;
+        }
+
+        public bool Remove(TKey1 key1)
+        {
+            bool found = false;
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterWriteLock();
+                    gotLock = true;
+                }
+
+                // This is an O(n) operation!
+                TValue value;
+                if (Dictionary1.TryGetValue(key1, out value))
+                {
+                    foreach (KeyValuePair<TKey2, TValue> kvp in Dictionary2)
+                    {
+                        if (kvp.Value.Equals(value))
+                        {
+                            Dictionary1.Remove(key1);
+                            Dictionary2.Remove(kvp.Key);
+                            found = true;
+                            break;
+                        }
+                    }
+                }
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitWriteLock(); 
+            }
+
+            return found;
+        }
+
+        public bool Remove(TKey2 key2)
+        {
+            bool found = false;
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterWriteLock();
+                    gotLock = true;
+                }
+
+                // This is an O(n) operation!
+                TValue value;
+                if (Dictionary2.TryGetValue(key2, out value))
+                {
+                    foreach (KeyValuePair<TKey1, TValue> kvp in Dictionary1)
+                    {
+                        if (kvp.Value.Equals(value))
+                        {
+                            Dictionary2.Remove(key2);
+                            Dictionary1.Remove(kvp.Key);
+                            found = true;
+                            break;
+                        }
+                    }
+                }
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitWriteLock(); 
+            }
+
+            return found;
+        }
+
+        public void Clear()
+        {
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterWriteLock();
+                    gotLock = true;
+                }
+
+                Dictionary1.Clear();
+                Dictionary2.Clear();
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitWriteLock(); 
+            }
+        }
+
+        public int Count
+        {
+            get { return Dictionary1.Count; }
+        }
+
+        public bool ContainsKey(TKey1 key)
+        {
+            return Dictionary1.ContainsKey(key);
+        }
+
+        public bool ContainsKey(TKey2 key)
+        {
+            return Dictionary2.ContainsKey(key);
+        }
+
+        public bool TryGetValue(TKey1 key, out TValue value)
+        {
+            bool success;
+            bool gotLock = false;
+
+            try 
+            { 
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                success = Dictionary1.TryGetValue(key, out value); 
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+
+            return success;
+        }
+
+        public bool TryGetValue(TKey2 key, out TValue value)
+        {
+            bool success;
+            bool gotLock = false;
+
+            try 
+            { 
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                success = Dictionary2.TryGetValue(key, out value); 
+            }
+            finally 
+            {   
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+
+            return success;
+        }
+
+        public void ForEach(Action<TValue> action)
+        {
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                foreach (TValue value in Dictionary1.Values)
+                    action(value);
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+        }
+
+        public void ForEach(Action<KeyValuePair<TKey1, TValue>> action)
+        {
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                foreach (KeyValuePair<TKey1, TValue> entry in Dictionary1)
+                    action(entry);
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+        }
+
+        public void ForEach(Action<KeyValuePair<TKey2, TValue>> action)
+        {
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                foreach (KeyValuePair<TKey2, TValue> entry in Dictionary2)
+                    action(entry);
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+        }
+
+        public TValue FindValue(Predicate<TValue> predicate)
+        {
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                foreach (TValue value in Dictionary1.Values)
+                {
+                    if (predicate(value))
+                        return value;
+                }
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+
+            return default(TValue);
+        }
+
+        public IList<TValue> FindAll(Predicate<TValue> predicate)
+        {
+            IList<TValue> list = new List<TValue>();
+            bool gotLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterReadLock();
+                    gotLock = true;
+                }
+
+                foreach (TValue value in Dictionary1.Values)
+                {
+                    if (predicate(value))
+                        list.Add(value);
+                }
+            }
+            finally 
+            { 
+                if (gotLock)
+                    rwLock.ExitReadLock(); 
+            }
+
+            return list;
+        }
+
+        public int RemoveAll(Predicate<TValue> predicate)
+        {
+            IList<TKey1> list = new List<TKey1>();
+            bool gotUpgradeableLock = false;
+
+            try
+            {
+                // Avoid an asynchronous Thread.Abort() from possibly never existing an acquired lock by placing
+                // the acquision inside the main try.  The inner finally block is needed because thread aborts cannot
+                // interrupt code in these blocks (hence gotLock is guaranteed to be set correctly).
+                try {}            
+                finally
+                {
+                    rwLock.EnterUpgradeableReadLock();
+                    gotUpgradeableLock = true;
+                }
+
+                foreach (KeyValuePair<TKey1, TValue> kvp in Dictionary1)
+                {
+                    if (predicate(kvp.Value))
+                        list.Add(kvp.Key);
+                }
+
+                IList<TKey2> list2 = new List<TKey2>(list.Count);
+                foreach (KeyValuePair<TKey2, TValue> kvp in Dictionary2)
+                {
+                    if (predicate(kvp.Value))
+                        list2.Add(kvp.Key);
+                }
+
+                bool gotWriteLock = false;
+
+                try
+                {
+                    try {}            
+                    finally
+                    {
+                        rwLock.EnterUpgradeableReadLock();
+                        gotWriteLock = true;
+                    }
+
+                    for (int i = 0; i < list.Count; i++)
+                        Dictionary1.Remove(list[i]);
+
+                    for (int i = 0; i < list2.Count; i++)
+                        Dictionary2.Remove(list2[i]);
+                }
+                finally 
+                { 
+                    if (gotWriteLock)
+                        rwLock.ExitWriteLock(); 
+                }
+            }
+            finally 
+            { 
+                if (gotUpgradeableLock)
+                    rwLock.ExitUpgradeableReadLock(); 
+            }
+
+            return list.Count;
+        }
+    }
+}
\ No newline at end of file
diff --git a/OpenSim/Region/Framework/Scenes/EntityManager.cs b/OpenSim/Region/Framework/Scenes/EntityManager.cs
index b788a3ca08..7181313fbe 100644
--- a/OpenSim/Region/Framework/Scenes/EntityManager.cs
+++ b/OpenSim/Region/Framework/Scenes/EntityManager.cs
@@ -31,6 +31,7 @@ using System.Collections.Generic;
 using System.Reflection;
 using log4net;
 using OpenMetaverse;
+using OpenSim.Framework;
 
 namespace OpenSim.Region.Framework.Scenes
 {
@@ -38,7 +39,8 @@ namespace OpenSim.Region.Framework.Scenes
     {
 //        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
         
-        private readonly DoubleDictionary<UUID, uint, EntityBase> m_entities = new DoubleDictionary<UUID, uint, EntityBase>();
+        private readonly DoubleDictionaryThreadAbortSafe<UUID, uint, EntityBase> m_entities 
+            = new DoubleDictionaryThreadAbortSafe<UUID, uint, EntityBase>();
 
         public int Count
         {