Problems with a Coalgirls' encode (1080p FLAC)

I've run across a weird issue. I'm trying to watch a series from Coalgirls, 1920x1080 H.264 with "XiFL stereo" (according to Quicktime 7; FLAC according to VLC and Coalgirls). Quicktime with Perian won't play sound; VLC 1.1.12 plays it perfectly, but it restarts the video after the first minute or two. Skipping past the restart point results in fine play for 5-10 minutes, but then the video restarts again. This seems to consistently happen across multiple episodes (I tested it and found it reproducible on three; didn't test beyond that). Processor usage is around 25%-45% per core with VLC, and slightly above 50% per core with Quicktime (dual-core processor). Operating system is OS X 10.7.2 - the mPlayer binary that I have was apparently a PPC program and 10.7 removed Rosetta support, so I can't test that.

Any suggestions?