AS3 - tackling memory leaks

So I’ve been working on a fairly large, AS3 app for some time now. It has tons of graphics, sounds, animations, a couple video clips, and almost 500 external class files or so. I’m just starting to notice that after extended play, some of the animations start acting a little choppy. I’m guessing I’ve got a memory leak.

I’ve determined / tracked these down before using Valgrind, but never had a reason to track them down in an AS app. Besides the obvious “dig through the code” and “handle memory efficiently to begin with” (which I thought I had), any extra tips to tackling memory leaks in AS3?