diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index 9c3f166b30..b5c8cf2efd 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -5526,11 +5526,12 @@ namespace OpenSim.Region.Framework.Scenes
             return -1;
         }
 
-        public void InvalidatePartsLinkMaps()
+        public void InvalidatePartsLinkMaps(bool all = true)
         {
             lock(m_partsNameToLinkMap)
             {
-                m_partsNameToLinkMap.Clear();
+                if(all)
+                    m_partsNameToLinkMap.Clear();
                 GetLinkNumber_lastname = String.Empty;
                 GetLinkNumber_lastnumber = -1;
             }
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
index c549f5c6a0..b427c1aef8 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
@@ -5638,8 +5638,8 @@ namespace OpenSim.Region.Framework.Scenes
                     if (m_sittingAvatars.Count == 0)
                         m_sittingAvatars = null;
 
-                    ParentGroup.m_sittingAvatars.Remove(sp);
-
+                    if(ParentGroup.m_sittingAvatars.Remove(sp))
+                        ParentGroup.InvalidatePartsLinkMaps(false);
                     return true;
                 }