diff --git a/OpenSim/Client/MXP/MXPModule.cs b/OpenSim/Client/MXP/MXPModule.cs
index 5873bf4a94..552c3b7100 100644
--- a/OpenSim/Client/MXP/MXPModule.cs
+++ b/OpenSim/Client/MXP/MXPModule.cs
@@ -57,7 +57,8 @@ namespace OpenSim.Client.MXP
 
         public void Initialise(Scene scene, IConfigSource source)
         {
-            m_scenes.Add(scene.RegionInfo.RegionID, scene);
+            if (!m_scenes.ContainsKey(scene.RegionInfo.RegionID))
+                m_scenes.Add(scene.RegionInfo.RegionID, scene);
             config = source;
         }