Bug#466145: And a final bit of information.

[William Lynch]

I discovered that "/usr/lib/gstreamer-0.10/libgstpostproc.so" was the  
plugin it would die on gstreamer0.10-ffmpeg-full (part of debian- 
multimedia).

I installed your version (gstreamer0.10-ffmpeg). And everything began  
to work. Then I reinstalled the full version.

Either version works now. I can't reproduce this any further... I  
guess close this bug. It would be nice if there was an easier way to  
figure this all out though.