Flash: Debugging unexplained sprites?

Question

I've been trying to debug a strange white rectangle that is appearing in my Flash application:

The standard debugging tools — binary search, breakpoints, hg bisect — have lead to dead ends.

Any suggestions tools I could use to debug this? Is there something like Firebug's inspector, which lets you mouse over HTML DOM elements to get information about them?

Answer 1

Don't the mouse events bubble as they do in the DOM? Could you not use the Sprite (or lower) Prototype to debug print?