BSOD - Random timing / situations 0x50

As the title states, random BSOD. Started a few weeks ago. *"On Mon 10/29/2012 3:28:36 AM GMT your computer crashed* crash dump file: C:\Windows\Minidump\102812-28563-01.dmp This was probably caused by the following module: ntoskrnl.exe (http://www.google.com/search?q=ntoskrnl.exe) (nt+0x7EFC0) Bugcheck code: 0x50 (0xFFFFF30012816930, 0x1, 0xFFFFF8000317818D, 0x7) Error:...