Re: nForce 4 corrupting data written to HDD
No one in the LKML thread you referenced reported files getting corrupted on-disk. This still sounds like a separate and unrelated problem, potentially with faulty hardware. Earlier you reported filesystem corruption at bootup. Do you have a log of the corruption errors? Have you run memtest86 to verify that your memory isn't faulty?
With respect to the jpg's getting corrupted, that sounds like the same issue as in the LKML posts, however in light of the filesystem corruption, its hard to say for certain whether you're not just hitting a variant. If you copy the same jpg file 100 times, what percentage of the time does it end up corrupted?
How many memory modules are you using, and which brand?