From: Alan Webb <alan_webb@us.ibm.com>

If an avatar is sitting when the client disconnects, the avatar
  is not disassociated from the SOG on which (s)he was sat. This
  produces any, and varied, effects.

  I have updated RemoveCLient in Scene, to check, and stand the
  client up immediately prior to disconnect. This seems like the
  most robust way to handle the situation. Though in this case
  it might be worth factoring out the animations from other
  standup processing. It does no harm, but in this case it is
  entirely redundant.

OpenSim/Region/Framework/Scenes/Scene.cs

@@ -2196,6 +2196,11 @@ namespace OpenSim.Region.Framework.Scenes
                 childagentYN = avatar.IsChildAgent;
             }
 
+            if (avatar.ParentID != 0)
+            {
+                avatar.StandUp();
+            }
+
             try
             {
                 m_log.DebugFormat(