It's usually when I'm doing some light multi-tasking, and just running a couple of applications at once. For example today I was running utorrent and an .avi file in quicktime and it started freezing intermittently. I've noticed that when iTunes or quicktime is open, it'll regularly freeze if I try to do anything else or open anything 3D orientated. I've noticed in the console I don't get any obvious crash errors as such, but npvhash 4095 tends to appear after a hard freeze. I've also had some modem errors claiming it isn't compatible as it's 64 bit. So far I've: -Taken it to Apple and their overnight testing/diagnostics have come back clear. -Reset PRAM -Reset SMC -Ran the Apple Hardware Test (extended)- all clear -Repaired Permissions -Verified OS Disk Drive -Erased and reinstalled OSX a number of times -Tried a different HDD -Verified Fonts (something I came accross when searching npvhash 4095 error) Overall, nothing has helped so I'm in the process of RMA'ing unless anyone here can come up with the solution Any ideas will be greatly appreciated.