Hi there, Right, I had the last version of Ubuntu (9.10 I think) and XBMC and was watching my HD movies on my acer revo 3610 without any problems. They were usually .mkv files and played fine. But then I upgraded to Ubuntu 10.04 and it's all gone, gone, gone. Whenever I play back my HD films they're all stuttery, slow and jerky and out of sync. I've tried changing the settings in XBMC but with no luck so far (tried setting render to VDPA but didn't fix it). I'm not even sure if the problem's with XBMC or the revo itself. I'm not sure if i need to update the nvidia drivers but then i'd imagine Ubuntu would remind me/do it when i upgraded. If you could help me I would be exceedingly grateful. Many thanks, Mike.