Disabling offline messages for AIM as we don't seem to support them properly at this point.

src/net/java/sip/communicator/impl/protocol/icq/OperationSetBasicInstantMessagingIcqImpl.java

@@ -381,7 +381,10 @@ private void assertConnected() throws IllegalStateException
      */
     public boolean isOfflineMessagingSupported()
     {
-        return true;
+        if(icqProvider.USING_ICQ)
+            return true;
+        else
+            return false;
     }
     
     /**