I just finished running Memtest+ v 4.10 on 4 memory sticks. Memtest shows different numbers than what's on the package and I wonder what's the difference. Memory is about a year old. 3 sticks passed, 1 failed. RMA submitted. I hope this explains all the corrupted files I've been getting.
Package Specs:
OCZ 2 x 2 GB (sorry Martin- it's not what I wanted at the time, but what I could get)

DDR3-1333
PC3-10666 CL
7 - 7 - 7 - 20
Memtest:
2048 MB PC3-8500
532 MHz (DDR3-1065)
CAS 7 - 7 - 7 - 19
So I'm running with 2 sticks now. i7-860, GA-P55A-UD2 MB, Corsair VX550W, GTX 460