diff -r 50bf9db68373 -r 33ae025ac1e8 metadataengine/server/src/mdsserversession.cpp
--- a/metadataengine/server/src/mdsserversession.cpp	Fri Apr 16 15:23:55 2010 +0300
+++ b/metadataengine/server/src/mdsserversession.cpp	Mon May 03 12:55:01 2010 +0300
@@ -69,7 +69,6 @@
 //
 void CMdSServerSession::ConstructL()
     {
-    iServer.IncrementSessions();
     }
 
 // ---------------------------------------------------------------------------
@@ -92,7 +91,6 @@
 
 	iServer.LockList().UnlockBySession( *this );
 	iServer.Notifier().RemoveEntriesBySession( *this );
-    iServer.DecrementSessions();
     
     // purge any pending notifications
 	iNotificationCache.ResetAndDestroy();
@@ -105,12 +103,25 @@
 //
 void CMdSServerSession::ServiceL( const RMessage2& aMessage )
     {
-    __LOG2( ELogServer, "ServiceL message: %d uid: %.8x", 
+    __LOG2( ELogServer, "ServiceL message: %d uid: %d", 
     		aMessage.Function(),
-    		aMessage.Identity());
-
+    		aMessage.Identity().iUid);
+    
 	if( iServer.BackupOrRestoreRunning() )
 		{
+        // Open client applications are closed during backup/restore,
+        // thus registered observers that would be removed during
+        // shutdown on clients, must be allowed to be removed even
+        // if backup/restore is running
+	    if( aMessage.Function() == EUnregister )
+	        {
+            TRAPD( err, ServiceFunctionL( aMessage ) );
+            if( err != KErrNone )
+                {
+                aMessage.Complete( err );
+                }
+            return;
+	        }
 		aMessage.Complete( KErrServerBusy );
 		return;
 		}
@@ -957,30 +968,42 @@
 
     CMdSNotifier::TEntry& entry = iServer.Notifier().FindEntryL( notifierId );
     entry.SetupForCallback( aMsg, 1 );
+
+    const TInt entryId = entry.Id();    
+
+    TInt low( 0 );
+    TInt high( iNotificationCache.Count() );
     
-	const TInt count = iNotificationCache.Count();
-	for( TInt i = 0; i < count; ++i )
-		{
-		const TInt notificationCacheId = iNotificationCache[i]->iId;
-		const TInt entryId = entry.Id();
+    while( low < high )
+        {
+        TInt mid( (low+high)>>1 );
+        
+        const TInt compare( entryId - iNotificationCache[mid]->iId );
+        if( compare == 0 )
+            {
+            // The cache holds a new notification for this notifier, trigger it
+            CNotificationCacheItem* item = iNotificationCache[mid];
+            iNotificationCache.Remove(mid);
 
-		if( notificationCacheId == entryId )
-			{
-			// The cache holds a new notification for this notifier, trigger it
-			CNotificationCacheItem* item = iNotificationCache[i];
-			iNotificationCache.Remove(i);
-
-			CleanupStack::PushL( item );
+            CleanupStack::PushL( item );
 
-			entry.TriggerCachedL( item->iCode, item->iData );
-			
-			// take ownership of iData from item and delete it
-			item->iData = NULL;
-			CleanupStack::PopAndDestroy( item );
-			
-			return;
-			}
-		}
+            entry.TriggerCachedL( item->iCode, item->iData );
+        
+            // take ownership of iData from item and delete it
+            item->iData = NULL;
+            CleanupStack::PopAndDestroy( item );
+        
+            return;
+            }
+        else if( compare > 0 )
+            {
+            low = mid + 1;
+            }
+        else
+            {
+            high = mid;
+            }
+        }
     }
 
 // ---------------------------------------------------------------------------
@@ -1180,7 +1203,8 @@
 	CleanupStack::Pop( aData );
 	CleanupStack::PushL( item );
 
-	iNotificationCache.AppendL( item );
+	iNotificationCache.InsertInOrderAllowRepeats( item, 
+	                              TLinearOrder<CNotificationCacheItem>(CMdSServerSession::ComparePropertiesCacheItem)); 
 
 	CleanupStack::Pop( item );
 	}
@@ -1640,3 +1664,8 @@
 	return KErrNone;
 	}
 
+TInt CMdSServerSession::ComparePropertiesCacheItem(const CNotificationCacheItem& aFirst, const CNotificationCacheItem& aSecond)
+    {
+    return aFirst.iId - aSecond.iId;
+    }
+