diff -r f979ecb2b13e -r 42814f902fe6 calendarui/commonutils/src/calenactionuiutils.cpp
--- a/calendarui/commonutils/src/calenactionuiutils.cpp	Tue Feb 02 10:12:19 2010 +0200
+++ b/calendarui/commonutils/src/calenactionuiutils.cpp	Fri Feb 19 22:49:53 2010 +0200
@@ -419,7 +419,7 @@
     // match the LocalUid to the incorrect instance in a series.
     for ( TInt i=0; i < instances.Count() && !result; ++i )
         {
-        if( instances[i]->Entry().LocalUidL() == aId.iEntryLocalUid )
+        if( (instances[i]->InstanceIdL().iCollectionId == aId.iColId) && (instances[i]->Entry().LocalUidL() == aId.iEntryLocalUid )) // comparing the collection id and Local Uid 
             {
             // Check the instance time matches.
             if( instances[i]->StartTimeL().TimeLocalL() == aId.iInstanceTime )