diff --git a/OpenSim/Framework/IClientAPI.cs b/OpenSim/Framework/IClientAPI.cs
index c1bd07886d..af76ea9825 100644
--- a/OpenSim/Framework/IClientAPI.cs
+++ b/OpenSim/Framework/IClientAPI.cs
@@ -749,14 +749,21 @@ namespace OpenSim.Framework
         /// </summary>
         string Name { get; }
 
-        /// <value>
-        /// Determines whether the client thread is doing anything or not.
-        /// </value>
+        /// <summary>
+        /// True if the client is active (sending and receiving new UDP messages).  False if the client is being closed.
+        /// </summary>
         bool IsActive { get; set; }
 
-        /// <value>
-        /// Determines whether the client is or has been removed from a given scene
-        /// </value>
+        /// <summary>
+        /// Set if the client is closing due to a logout request
+        /// </summary>
+        /// <remarks>
+        /// Do not use this flag if you want to know if the client is closing, since it will not be set in other
+        /// circumstances (e.g. if a child agent is closed or the agent is kicked off the simulator).  Use IsActive
+        /// instead with a IClientAPI.SceneAgent.IsChildAgent check if necessary.
+        ///
+        /// Only set for root agents.
+        /// </remarks>
         bool IsLoggingOut { get; set; }
         
         bool SendLogoutPacketWhenClosing { set; }
diff --git a/OpenSim/Framework/ISceneAgent.cs b/OpenSim/Framework/ISceneAgent.cs
index 824172d58a..563d906b7f 100644
--- a/OpenSim/Framework/ISceneAgent.cs
+++ b/OpenSim/Framework/ISceneAgent.cs
@@ -26,6 +26,7 @@
  */
 
 using System;
+using OpenMetaverse;
 
 namespace OpenSim.Framework
 {
@@ -71,5 +72,11 @@ namespace OpenSim.Framework
         /// This includes scene object data and the appearance data of other avatars.
         /// </remarks>
         void SendInitialDataToMe();
+
+        /// <summary>
+        /// Direction in which the scene presence is looking.
+        /// </summary>
+        /// <remarks>Will be Vector3.Zero for a child agent.</remarks>
+        Vector3 Lookat { get; }        
     }
 }
\ No newline at end of file
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
index 18d8045fe0..b40eeed41d 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
@@ -515,6 +515,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// </summary>
         public void Close(bool sendStop)
         {
+            IsActive = false;
+
             m_log.DebugFormat(
                 "[CLIENT]: Close has been called for {0} attached to scene {1}",
                 Name, m_scene.RegionInfo.RegionName);
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
index 3c23dcff8d..22cc1940bd 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
@@ -555,12 +555,17 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             if (udpClient.IsPaused)
                 timeoutTicks = m_pausedAckTimeout;
 
-            if (!client.IsLoggingOut &&
+            if (client.IsActive &&
                 (Environment.TickCount & Int32.MaxValue) - udpClient.TickLastPacketReceived > timeoutTicks)
             {
-                m_log.Warn("[LLUDPSERVER]: Ack timeout, disconnecting " + udpClient.AgentID);
-                StatsManager.SimExtraStats.AddAbnormalClientThreadTermination();
-                RemoveClient(client);
+                // We must set IsActive synchronously so that we can stop the packet loop reinvoking this method, even
+                // though it's set later on by LLClientView.Close()
+                client.IsActive = false;
+
+                // Fire this out on a different thread so that we don't hold up outgoing packet processing for
+                // everybody else if this is being called due to an ack timeout.
+                // This is the same as processing as the async process of a logout request.
+                Util.FireAndForget(o => DeactivateClientDueToTimeout(client));
 
                 return;
             }
@@ -1110,9 +1115,29 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             return client;
         }
 
-        private void RemoveClient(IClientAPI client)
+        /// <summary>
+        /// Deactivates the client if we don't receive any packets within a certain amount of time (default 60 seconds).
+        /// </summary>
+        /// <remarks>
+        /// If a connection is active then we will always receive packets even if nothing else is happening, due to
+        /// regular client pings.
+        /// </remarks>
+        /// <param name='client'></param>
+        private void DeactivateClientDueToTimeout(IClientAPI client)
         {
-            client.IsLoggingOut = true;
+            // We must set IsActive synchronously so that we can stop the packet loop reinvoking this method, even
+            // though it's set later on by LLClientView.Close()
+            client.IsActive = false;
+
+            m_log.WarnFormat(
+                "[LLUDPSERVER]: Ack timeout, disconnecting {0} agent for {1} in {2}",
+                client.SceneAgent.IsChildAgent ? "child" : "root", client.Name, m_scene.RegionInfo.RegionName);
+
+            StatsManager.SimExtraStats.AddAbnormalClientThreadTermination();
+
+            if (!client.SceneAgent.IsChildAgent)
+                 client.Kick("Simulator logged you out due to connection timeout");
+
             Util.FireAndForget(o => client.Close());
         }
 
@@ -1429,8 +1454,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         protected void LogoutHandler(IClientAPI client)
         {
             client.SendLogoutPacket();
+
             if (!client.IsLoggingOut)
-                RemoveClient(client);
+            {
+                client.IsLoggingOut = true;
+                client.Close();
+            }
         }
     }
 }
diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
index 7e71fd18eb..3010b59f13 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
@@ -328,34 +328,30 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
         void OnConnectionClosed(IClientAPI obj)
         {
-            if (obj.IsLoggingOut)
+            if (obj.SceneAgent.IsChildAgent)
+                return;
+
+            // Let's find out if this is a foreign user or a local user
+            IUserManagement uMan = Scene.RequestModuleInterface<IUserManagement>();
+//          UserAccount account = Scene.UserAccountService.GetUserAccount(Scene.RegionInfo.ScopeID, obj.AgentId);
+
+            if (uMan != null && uMan.IsLocalGridUser(obj.AgentId))
             {
-                object sp = null;
-                if (obj.Scene.TryGetScenePresence(obj.AgentId, out sp))
-                {
-                    if (((ScenePresence)sp).IsChildAgent)
-                        return;
-                }
+                // local grid user
+                return;
+            }
 
-                // Let's find out if this is a foreign user or a local user
-                IUserManagement uMan = Scene.RequestModuleInterface<IUserManagement>();
-//                UserAccount account = Scene.UserAccountService.GetUserAccount(Scene.RegionInfo.ScopeID, obj.AgentId);
-                if (uMan != null && uMan.IsLocalGridUser(obj.AgentId))
-                {
-                    // local grid user
-                    return;
-                }
+            AgentCircuitData aCircuit = ((Scene)(obj.Scene)).AuthenticateHandler.GetAgentCircuitData(obj.CircuitCode);
 
-                AgentCircuitData aCircuit = ((Scene)(obj.Scene)).AuthenticateHandler.GetAgentCircuitData(obj.CircuitCode);
-
-                if (aCircuit.ServiceURLs.ContainsKey("HomeURI"))
-                {
-                    string url = aCircuit.ServiceURLs["HomeURI"].ToString();
-                    IUserAgentService security = new UserAgentServiceConnector(url);
-                    security.LogoutAgent(obj.AgentId, obj.SessionId);
-                    //m_log.DebugFormat("[HG ENTITY TRANSFER MODULE]: Sent logout call to UserAgentService @ {0}", url);
-                }
-                else
+            if (aCircuit.ServiceURLs.ContainsKey("HomeURI"))
+            {
+                string url = aCircuit.ServiceURLs["HomeURI"].ToString();
+                IUserAgentService security = new UserAgentServiceConnector(url);
+                security.LogoutAgent(obj.AgentId, obj.SessionId);
+                //m_log.DebugFormat("[HG ENTITY TRANSFER MODULE]: Sent logout call to UserAgentService @ {0}", url);
+            }
+            else
+            {
                     m_log.DebugFormat("[HG ENTITY TRANSFER MODULE]: HomeURI not found for agent {0} logout", obj.AgentId);
             }
         }
diff --git a/OpenSim/Region/CoreModules/ServiceConnectorsOut/GridUser/ActivityDetector.cs b/OpenSim/Region/CoreModules/ServiceConnectorsOut/GridUser/ActivityDetector.cs
index 4cf62eca54..b0edce7a91 100644
--- a/OpenSim/Region/CoreModules/ServiceConnectorsOut/GridUser/ActivityDetector.cs
+++ b/OpenSim/Region/CoreModules/ServiceConnectorsOut/GridUser/ActivityDetector.cs
@@ -79,29 +79,13 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.GridUser
 
         public void OnConnectionClose(IClientAPI client)
         {
-            if (client.IsLoggingOut)
-            {
-                object sp = null;
-                Vector3 position = new Vector3(128, 128, 0);
-                Vector3 lookat = new Vector3(0, 1, 0);
-
-                if (client.Scene.TryGetScenePresence(client.AgentId, out sp))
-                {
-                    if (sp is ScenePresence)
-                    {
-                        if (((ScenePresence)sp).IsChildAgent)
-                            return;
-
-                        position = ((ScenePresence)sp).AbsolutePosition;
-                        lookat = ((ScenePresence)sp).Lookat;
-                    }
-                }
-
-//                m_log.DebugFormat("[ACTIVITY DETECTOR]: Detected client logout {0} in {1}", client.AgentId, client.Scene.RegionInfo.RegionName);
-                m_GridUserService.LoggedOut(client.AgentId.ToString(), client.SessionId, client.Scene.RegionInfo.RegionID, position, lookat);
-            }
+            if (client.SceneAgent.IsChildAgent)
+                return;
 
+//            m_log.DebugFormat("[ACTIVITY DETECTOR]: Detected client logout {0} in {1}", client.AgentId, client.Scene.RegionInfo.RegionName);
+            m_GridUserService.LoggedOut(
+                client.AgentId.ToString(), client.SessionId, client.Scene.RegionInfo.RegionID,
+                client.SceneAgent.AbsolutePosition, client.SceneAgent.Lookat);
         }
-
     }
 }
diff --git a/OpenSim/Region/CoreModules/ServiceConnectorsOut/Presence/PresenceDetector.cs b/OpenSim/Region/CoreModules/ServiceConnectorsOut/Presence/PresenceDetector.cs
index ccfbf78a29..172bea10e3 100644
--- a/OpenSim/Region/CoreModules/ServiceConnectorsOut/Presence/PresenceDetector.cs
+++ b/OpenSim/Region/CoreModules/ServiceConnectorsOut/Presence/PresenceDetector.cs
@@ -64,7 +64,6 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.Presence
             scene.EventManager.OnNewClient -= OnNewClient;
 
             m_PresenceService.LogoutRegionAgents(scene.RegionInfo.RegionID);
-
         }
 
         public void OnMakeRootAgent(ScenePresence sp)
@@ -80,18 +79,8 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.Presence
 
         public void OnConnectionClose(IClientAPI client)
         {
-            if (client.IsLoggingOut)
+            if (!client.SceneAgent.IsChildAgent)
             {
-                object sp = null;
-                if (client.Scene.TryGetScenePresence(client.AgentId, out sp))
-                {
-                    if (sp is ScenePresence)
-                    {
-                        if (((ScenePresence)sp).IsChildAgent)
-                            return;
-                    }
-                }
-
 //                m_log.DebugFormat("[PRESENCE DETECTOR]: Detected client logout {0} in {1}", client.AgentId, client.Scene.RegionInfo.RegionName);
                 m_PresenceService.LogoutAgent(client.SessionId);
             }
diff --git a/OpenSim/Region/Framework/Scenes/AsyncInventorySender.cs b/OpenSim/Region/Framework/Scenes/AsyncInventorySender.cs
index 9cb567430b..d9d2e64d87 100644
--- a/OpenSim/Region/Framework/Scenes/AsyncInventorySender.cs
+++ b/OpenSim/Region/Framework/Scenes/AsyncInventorySender.cs
@@ -137,7 +137,7 @@ namespace OpenSim.Region.Framework.Scenes
                     }
                 }
 
-                if (fh.Client.IsLoggingOut)
+                if (!fh.Client.IsActive)
                     continue;
 
 //                m_log.DebugFormat(
diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index 3095382262..85bae9ab63 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -3617,10 +3617,9 @@ namespace OpenSim.Region.Framework.Scenes
                 // Or the same user is trying to be root twice here, won't work.
                 // Kill it.
                 m_log.DebugFormat(
-                    "[SCENE]: Zombie scene presence detected for {0} in {1}",
-                    agent.AgentID,
-                    RegionInfo.RegionName
-                );
+                    "[SCENE]: Zombie scene presence detected for {0} {1} in {2}",
+                    sp.Name, sp.UUID, RegionInfo.RegionName);
+
                 sp.ControllingClient.Close();
                 sp = null;
             }
diff --git a/OpenSim/Services/Connectors/SimianGrid/SimianActivityDetector.cs b/OpenSim/Services/Connectors/SimianGrid/SimianActivityDetector.cs
index 2267325bdc..95e4bab134 100644
--- a/OpenSim/Services/Connectors/SimianGrid/SimianActivityDetector.cs
+++ b/OpenSim/Services/Connectors/SimianGrid/SimianActivityDetector.cs
@@ -79,27 +79,13 @@ namespace OpenSim.Services.Connectors.SimianGrid
 
         public void OnConnectionClose(IClientAPI client)
         {
-            if (client.IsLoggingOut)
-            {
-                object sp = null;
-                Vector3 position = new Vector3(128, 128, 0);
-                Vector3 lookat = new Vector3(0, 1, 0);
+            if (client.SceneAgent.IsChildAgent)
+                return;
 
-                if (client.Scene.TryGetScenePresence(client.AgentId, out sp))
-                {
-                    if (sp is ScenePresence)
-                    {
-                        if (((ScenePresence)sp).IsChildAgent)
-                            return;
-
-                        position = ((ScenePresence)sp).AbsolutePosition;
-                        lookat = ((ScenePresence)sp).Lookat;
-                    }
-                }
-
-//                m_log.DebugFormat("[SIMIAN ACTIVITY DETECTOR]: Detected client logout {0} in {1}", client.AgentId, client.Scene.RegionInfo.RegionName);
-                m_GridUserService.LoggedOut(client.AgentId.ToString(), client.SessionId, client.Scene.RegionInfo.RegionID, position, lookat);
-            }
+//            m_log.DebugFormat("[ACTIVITY DETECTOR]: Detected client logout {0} in {1}", client.AgentId, client.Scene.RegionInfo.RegionName);
+            m_GridUserService.LoggedOut(
+                client.AgentId.ToString(), client.SessionId, client.Scene.RegionInfo.RegionID,
+                client.SceneAgent.AbsolutePosition, client.SceneAgent.Lookat);
         }
 
         void OnEnteringNewParcel(ScenePresence sp, int localLandID, UUID regionID)
@@ -111,4 +97,4 @@ namespace OpenSim.Services.Connectors.SimianGrid
             });
         }
     }
-}
+}
\ No newline at end of file