diff --git a/ComIOP/Common/Client/Da/ComDaClientNodeManager.cs b/ComIOP/Common/Client/Da/ComDaClientNodeManager.cs
index f203545e5..89497a1f2 100644
--- a/ComIOP/Common/Client/Da/ComDaClientNodeManager.cs
+++ b/ComIOP/Common/Client/Da/ComDaClientNodeManager.cs
@@ -825,7 +825,6 @@ protected override ServiceResult CreateMonitoredItem(ServerSystemContext context
             monitoredItem = datachangeItem;
 
             // save the monitored item.
-            MonitoredItems.Add(monitoredItemId, datachangeItem);
             monitoredNode.Add(datachangeItem);
 
             // report change.