I have the same problem, I've tried ALL fixes posted in this thread to no avail. I have a very fast machine running Win7 x64. Intel 2600k @ 4.7Ghz and a GTX580 with 16Gb RAM, I'm running a 120hz primary monitor @ 1080p with a 1080p projector @ 60hz as my 2nd monitor, when I play .MKV videos full scr...