 			setInternalColumn(null); // this will remove the callback that was added to the internal column
 		}
 		
+		private var _overrideTitle:String;
+		
 		/**
 		 * Call this function when the ProxyColumn should indicate that the requested data is unavailable.
 		 * @param message The message to display in the title of the ProxyColumn. Default is "Data unavailable."

			return _internalColumn;
		}
		public function setInternalColumn(newColumn:IAttributeColumn):void
		{
			if (newColumn == this)
			{
				trace("WARNING! Attempted to set ProxyColumn.internalAttributeColumn to self: " + this);

		public function dataUnavailable(message:String = null):void
		{
			delayCallbacks();
			setInternalColumn(null);
			_overrideTitle = message || lang("Data unavailable");
			triggerCallbacks();
			resumeCallbacks();
		}
			
