diff --git a/OpenSim/Region/Framework/Interfaces/INPCModule.cs b/OpenSim/Region/Framework/Interfaces/INPCModule.cs
index 5e5c4a1e14..9dd8c79a5f 100644
--- a/OpenSim/Region/Framework/Interfaces/INPCModule.cs
+++ b/OpenSim/Region/Framework/Interfaces/INPCModule.cs
@@ -94,6 +94,15 @@ namespace OpenSim.Region.Framework.Interfaces
         /// <returns>True if the operation succeeded, false if there was no such agent or the agent was not an NPC</returns>
         bool Say(UUID agentID, Scene scene, string text);
 
+        /// <summary>
+        /// Sit the NPC.
+        /// </summary>
+        /// <param name="agentID"></param>
+        /// <param name="partID"></param>
+        /// <param name="scene"></param>
+        /// <returns>true if the sit succeeded, false if not</returns>
+        bool Sit(UUID agentID, UUID partID, Scene scene);
+
         /// <summary>
         /// Delete an NPC.
         /// </summary>
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index fae161857f..5381f63bfa 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -493,8 +493,8 @@ namespace OpenSim.Region.Framework.Scenes
                 {
                     foreach (ScenePresence av in m_linkedAvatars)
                     {
-                        SceneObjectPart p;
-                        if (m_parts.TryGetValue(av.LinkedPrim, out p))
+                        SceneObjectPart p = m_scene.GetSceneObjectPart(av.ParentID);
+                        if (m_parts.TryGetValue(p.UUID, out p))
                         {
                             Vector3 offset = p.GetWorldPosition() - av.ParentPosition;
                             av.AbsolutePosition += offset;
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
index d7435c6580..89b98af3eb 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
@@ -776,7 +776,7 @@ namespace OpenSim.Region.Framework.Scenes
                         List<ScenePresence> avs = ParentGroup.GetLinkedAvatars();
                         foreach (ScenePresence av in avs)
                         {
-                            if (av.LinkedPrim == m_uuid)
+                            if (av.ParentID == m_localId)
                             {
                                 Vector3 offset = (m_offsetPosition - oldpos);
                                 av.AbsolutePosition += offset;
@@ -1260,14 +1260,12 @@ namespace OpenSim.Region.Framework.Scenes
         	set { m_occupied = value; }
         }
 
-        
         public UUID SitTargetAvatar
         {
             get { return m_sitTargetAvatar; }
             set { m_sitTargetAvatar = value; }
         }
 
-        
         public virtual UUID RegionID
         {
             get
diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index bdfad40e8f..bb65322e97 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -671,19 +671,12 @@ namespace OpenSim.Region.Framework.Scenes
         private uint m_parentID;
 
 
-        private UUID m_linkedPrim;
-
         public uint ParentID
         {
             get { return m_parentID; }
             set { m_parentID = value; }
         }
 
-        public UUID LinkedPrim
-        {
-            get { return m_linkedPrim; }
-            set { m_linkedPrim = value; }
-        }
 
         public float Health
         {
@@ -2056,7 +2049,6 @@ namespace OpenSim.Region.Framework.Scenes
                 
 		        m_parentPosition = Vector3.Zero;
 				m_parentID = 0;
-                m_linkedPrim = UUID.Zero;
                 m_offsetRotation = new Quaternion(0.0f, 0.0f, 0.0f, 1.0f);
                 SendAvatarDataToAllAgents();
                 m_requestedSitTargetID = 0;
@@ -2513,7 +2505,6 @@ namespace OpenSim.Region.Framework.Scenes
         }
         */
 
-
         public void HandleAgentSit(IClientAPI remoteClient, UUID agentID)
         {
             if (!String.IsNullOrEmpty(m_nextSitAnimation))
@@ -2616,7 +2607,6 @@ namespace OpenSim.Region.Framework.Scenes
                 m_parentID = m_requestedSitTargetID;
             }
 
-            m_linkedPrim = part.UUID;
             if (part.GetAvatarOnSitTarget() != UUID)
             {
                 m_offsetRotation = m_offsetRotation / part.RotationOffset;
diff --git a/OpenSim/Region/OptionalModules/World/NPC/NPCModule.cs b/OpenSim/Region/OptionalModules/World/NPC/NPCModule.cs
index bcd9e943ee..be736393b5 100644
--- a/OpenSim/Region/OptionalModules/World/NPC/NPCModule.cs
+++ b/OpenSim/Region/OptionalModules/World/NPC/NPCModule.cs
@@ -199,6 +199,24 @@ namespace OpenSim.Region.OptionalModules.World.NPC
             return false;
         }
 
+        public bool Sit(UUID agentID, UUID partID, Scene scene)
+        {
+            lock (m_avatars)
+            {
+                if (m_avatars.ContainsKey(agentID))
+                {
+                    ScenePresence sp;
+                    scene.TryGetScenePresence(agentID, out sp);
+                    sp.HandleAgentRequestSit(m_avatars[agentID], agentID, partID, Vector3.Zero);
+                    sp.HandleAgentSit(m_avatars[agentID], agentID);
+
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
         public bool DeleteNPC(UUID agentID, Scene scene)
         {
             lock (m_avatars)
diff --git a/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs b/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs
index 49c06bcfcd..c5be0b69a9 100644
--- a/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs
+++ b/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs
@@ -229,5 +229,29 @@ namespace OpenSim.Region.OptionalModules.World.NPC.Tests
             Assert.That(distanceToTarget, Is.LessThan(1), "NPC not within 1 unit of target position on second move");
             Assert.That(npc.AbsolutePosition, Is.EqualTo(targetPos));
         }
+
+        [Test]
+        public void TestSit()
+        {
+            TestHelpers.InMethod();
+//            log4net.Config.XmlConfigurator.Configure();
+
+            ScenePresence sp = SceneHelpers.AddScenePresence(scene, TestHelpers.ParseTail(0x1));
+
+            Vector3 startPos = new Vector3(128, 128, 30);
+            INPCModule npcModule = scene.RequestModuleInterface<INPCModule>();
+            UUID npcId = npcModule.CreateNPC("John", "Smith", startPos, scene, sp.Appearance);
+
+            ScenePresence npc = scene.GetScenePresence(npcId);
+            SceneObjectPart part = SceneHelpers.AddSceneObject(scene);
+
+            // We must have a non Vector3.Zero sit target position otherwise part.SitTargetAvatar doesn't get set!
+            part.SitTargetPosition = new Vector3(0, 0, 1);
+            npcModule.Sit(npc.UUID, part.UUID, scene);
+
+            // Assertions?
+            Assert.That(part.SitTargetAvatar, Is.EqualTo(npcId));
+            Assert.That(npc.ParentID, Is.EqualTo(part.LocalId));
+        }
     }
 }
\ No newline at end of file
diff --git a/OpenSim/Region/Physics/OdePlugin/OdeScene.cs b/OpenSim/Region/Physics/OdePlugin/OdeScene.cs
index fc45b82a68..ffcb004e96 100644
--- a/OpenSim/Region/Physics/OdePlugin/OdeScene.cs
+++ b/OpenSim/Region/Physics/OdePlugin/OdeScene.cs
@@ -687,6 +687,7 @@ namespace OpenSim.Region.Physics.OdePlugin
         /// <param name="g2">another geometry or space</param>
         private void near(IntPtr space, IntPtr g1, IntPtr g2)
         {
+//            m_log.DebugFormat("[PHYSICS]: Colliding {0} and {1} in {2}", g1, g2, space);
             //  no lock here!  It's invoked from within Simulate(), which is thread-locked
 
             // Test if we're colliding a geom with a space.
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
index b19f8cfea1..bfe62c7a23 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
@@ -2359,6 +2359,17 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             }
         }
 
+        public void osNpcSit(LSL_Key npc, LSL_Key target, int options)
+        {
+            CheckThreatLevel(ThreatLevel.High, "osNpcSit");
+
+            INPCModule module = World.RequestModuleInterface<INPCModule>();
+            if (module != null)
+            {
+                module.Sit(new UUID(npc.m_string), new UUID(target.m_string), World);
+            }
+        }
+
         public void osNpcRemove(LSL_Key npc)
         {
             CheckThreatLevel(ThreatLevel.High, "osNpcRemove");
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs
index 5ddba60ea7..8fe43dd6a0 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs
@@ -178,6 +178,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api.Interfaces
         void osNpcSetRot(LSL_Key npc, rotation rot);
         void osNpcStopMoveToTarget(LSL_Key npc);
         void osNpcSay(key npc, string message);
+        void osNpcSit(key npc, key target, int options);
         void osNpcRemove(key npc);
 
         LSL_Key osOwnerSaveAppearance(string notecard);
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/LSL_Constants.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/LSL_Constants.cs
index 864d59c075..be5165045c 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/LSL_Constants.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/LSL_Constants.cs
@@ -603,6 +603,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.ScriptBase
         public const int OS_NPC_NO_FLY = 1;
         public const int OS_NPC_LAND_AT_TARGET = 2;
 
+        public const int OS_NPC_SIT_IMMEDIATE = 0;
+
         public const string URL_REQUEST_GRANTED = "URL_REQUEST_GRANTED";
         public const string URL_REQUEST_DENIED = "URL_REQUEST_DENIED";
 
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs
index bbc8cc6029..38391dfbb6 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs
@@ -528,6 +528,11 @@ namespace OpenSim.Region.ScriptEngine.Shared.ScriptBase
             m_OSSL_Functions.osNpcSay(npc, message);
         }
 
+        public void osNpcSit(LSL_Key npc, LSL_Key target, int options)
+        {
+            m_OSSL_Functions.osNpcSit(npc, target, options);
+        }
+
         public void osNpcRemove(key npc)
         {
             m_OSSL_Functions.osNpcRemove(npc);