I think I made my buffer large because I stream a lot so it's probably a gig or so and the files are mostly shows at 350mb or a movie at 700 mb. I stream divx stuff from
NinjaVideo.net or
IceFilms.info - HQ DivX TV & Movies and I'm pretty sure the whole thing get's dl'd to the temp folder.
I played a second video that is still in the temp folder from the day before but no longer used by my browser and it played fine in WMPC so the file is fine to play it's just making the file not disappear when the temp folder gets flushed is the problem.