Fix the order of operations on detach. The object must always be serialized

while still in the scene to avoid losing important script state.
DeleteSceneObject can not be called before doing this!

OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs

@@ -757,18 +757,22 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
             m_scene.EventManager.TriggerOnAttach(so.LocalId, so.FromItemID, UUID.Zero);
             sp.RemoveAttachment(so);
 
-            // We can only remove the script instances from the script engine after we've retrieved their xml state
-            // when we update the attachment item.
-            m_scene.DeleteSceneObject(so, false, false);
-
             // Prepare sog for storage
             so.AttachedAvatar = UUID.Zero;
             so.RootPart.SetParentLocalId(0);
             so.IsAttachment = false;
-            so.AbsolutePosition = so.RootPart.AttachedPos;
+
+            // We cannot use AbsolutePosition here because that would
+            // attempt to cross the prim as it is detached
+            so.ForEachPart(x => { x.GroupPosition = so.RootPart.AttachedPos; });
 
             UpdateKnownItem(sp, so, true);
-            so.RemoveScriptInstances(true);
+
+            // This MUST happen AFTER serialization because it will
+            // either stop or remove the scripts. Both will cause scripts
+            // to be serialized in a stopped state with the true run
+            // state already lost.
+            m_scene.DeleteSceneObject(so, false, true);
         }
 
         protected SceneObjectGroup RezSingleAttachmentFromInventoryInternal(