 			// For Containers we need to add the mask
 			// to the "allChildren" collection so it doesn't get
 			// treated as a content child.
-			if (target is Container)
+			if (target is IContainer)
 				target.rawChildren.addChild(effectMask); 
 			else
 				target.addChild(effectMask); 

		}

		if (invalidateBorder)
			IInvalidating(Container(target).border).invalidateDisplayList();
	}

	/** 

			}		
		}
		
		invalidateBorder = target is IContainer &&
                           "border" in target && 
						   target["border"] != null &&
                           target["border"] is IInvalidating && 
						   DisplayObject(target["border"]).filters != null;
	}
	
	/**
