A long while ago I wrote an article describing how to block background elements in Flash. The problem I used to encounter was that my background elements were clickable through other movie clips on the stage.
Recently, I’ve had the opportunity to use Flash CS3 and ActionScript 3.0 and my problems with click handling have been flipped upside-down. The annoyance I encounter now, is that I cannot click through movie clips, even if their alpha is set to be completely transparent. For example, if I have a series of clickable movie clips positioned under another clip acting as a glare.