Slightly out of left field as I doubt many people have kit that is relevant to this problem, but it is worth flaggin up as many people are considering a 64-bit upgrade. Had I gone ahead with my upgrade for the LAN (aka I got some unexpected bills :() then I would have had kit that _may_ have suffered this problem.
If Tag Command Queuing/Native Command Queuing (used by Western Digital and Seagate respectively) and hard drive corruption soudn in the least bit interesting when coupled with a TCQ/NCQ compatible NF4 motherboard then have a quick read here (http://www.amdgamer.com/read.php?rid=136&type=1) as it could save you hours of fruitless reinstalling.
TL.