Weird... When I try to load external pngs, the file loads but displays as a solid red color. Loading a jpg using the same code works fine.

What gives?

Ah... Turns out I was running into the bitmap size limit. The png is 6296x420 whereas the jpg is 500x500, hence the initial belief it was a file type issue. Placing the png in its own swf and loading that instead works great.