 			if (_allKeysTriggerCount != variables.triggerCounter)
 			{
 				_allKeys = null;
+				_allKeysLookup = new Dictionary(true);
 				_allKeysTriggerCount = variables.triggerCounter; // prevent infinite recursion
 
 				var variableColumns:Array = variables.getObjects(IKeySet);

		 */
		override public function containsKey(key:IQualifiedKey):Boolean
		{
			return !StandardLib.isUndefined(getValueFromKey(key));
		}

		private function variableGetter(name:String):*

					var keyType:String = this.getMetadata(ColumnMetadata.KEY_TYPE);
					_allKeys = _allKeys.filter(new KeyFilterFunction(keyType).filter);
				}
				VectorUtils.fillKeys(_allKeysLookup, _allKeys);
			}
			return _allKeys || [];
		}
