VDPAU crashes trying to play almost any h.264 video with an 8400M, even Grey.ts. Here's the trace on a 720p video.
NVRM: Xid (0005:00): 13, 0004 00000000 00008297 000019d0 0000003c 00000100
this happens regardless of container, for almost every h.264 video I've tried playing.
Here's another trace on a 480p file which fails a little later.
Stopping X, reloading the nvidia module, and restarting X allow the 480p video correctly, however if I try to play Grey.ts it still crashes.