Don't be too sure it's necessarily the harddrive giving you grief. It could be that your ram is flakey and you should try less aggressive timings or different ram altogether. These symptoms occurred to me once and it was the ram that was the trouble. It seems my motherboard doesn't like to use pairs of dimms very much or aggressive timings. Try running memtest86 (google it) on your machine and see if it comes out clean.
__________________
Laptop:
1.6@2.13 Dothan 2MB (Pinmod), 2 GB 533mhz DDR2, GeForce 6800 360/730 256MB, 100 GB 5400 RPM, 17" UXGA+