Re: nForce 4 corrupting data written to HDD
Are you stating that the original debian-update-3.1r4-i386-1.iso that you copied has had its md5sum change over time, even though its not been touched in any way?
With regard to the jpg's in your Problem.zip, I've just copied them from one SATA disk to another, and their md5sums have remained the same. Do these images consistantly get corrupted every time you copy them?
Have you verified that you're using the latest BIOS for the motherboard?
Additionally, please provide output from the following commands: