i have installed swfdec 0.5.1 in feisty fawn, i cannot try it at the momentan on a other plattform but the folling youtube video reproducable crash my epiphany when i start the movie:
Woah, the error handling code in Swfdec's ffmpeg decoder really needed some help.
The video in that link is pretty busted, but it plays now. (I checked in mplayer, and mplayer doesn't like it either.) It definitely doesn't crash anymore at least.