--- a/uifw/AvKon/src/aknApp.cpp	Tue Apr 27 16:55:05 2010 +0300
+++ b/uifw/AvKon/src/aknApp.cpp	Tue May 11 16:27:42 2010 +0300
@@ -31,6 +31,7 @@
 #include <UikonInternalPSKeys.h>
 #include <e32property.h>
 #include <AknSgcc.h>
+#include <w32std.h>
 
 LOCAL_C TBool IsInHiddenList(const TUid& aUid)
 	{
@@ -64,15 +65,40 @@
 		CApaWindowGroupName* wgName = CApaWindowGroupName::NewLC(ws, myWg);
 		wgName->SetAppUid(uid);
 		wgName->SetWindowGroupName(env->RootWin());
-
-		// Use a CAknTaskList to check for root instances of apps
-		CAknTaskList* taskList = CAknTaskList::NewLC(ws);
-		TBool foundInstance = EFalse;
-		
+	      
+        // Use a CAknTaskList to check for root instances of apps
+        CAknTaskList* taskList = CAknTaskList::NewLC(ws);
+        TBool foundInstance = EFalse;
+	    
 		// Look for another instance of this app
 		while (wgId>=0)
 			{
-			if (wgId && wgId != myWg && taskList->IsRootWindowGroup(wgId))
+		    TBool rootTask = taskList->IsRootWindowGroup(wgId);
+		    TBool rootWg = EFalse;
+		    TInt wndPriority = -1;
+		    if ( wgId != myWg && wgId > 0  && !rootTask )
+		        {
+                wndPriority = ws.GetWindowGroupOrdinalPriority( wgId );
+                RArray<RWsSession::TWindowGroupChainInfo> wgs;
+                // it seems effecient to call WindowGroupList here, this codes will seldom executed.
+                ws.WindowGroupList( wndPriority,  &wgs );
+                   
+                TInt count = wgs.Count();
+                for ( TInt ii=0; ii<count; ii++ )
+                    {
+                    const RWsSession::TWindowGroupChainInfo& info = wgs[ii];
+                    // find the window group id and check that it has no parent
+                    if ( info.iId == wgId )
+                        {
+                        rootWg = (info.iParentId <= 0);
+                        break;
+                        }
+                    }
+                
+                wgs.Close();
+		        }
+		    
+			if (wgId && wgId != myWg  &&  ( rootWg || rootTask ) )
 				{	// found another app, switch to it & die
 				/*
 				TApaTask other(ws);