Round cables = signal crosstalk = corrupt data = reformat HD.
If you don't believe me. Well, I don't care.

It's YOUR data!
ATA66 and 100 (and 133 I assume) by design are "flat" cables with a ground between each signal wire. ATA66+ will not work properly with any other cable. (sure, the drive
will work)
Don't worry, I've caught much flame for saying it... but Ribbon cables were disigned flat for a reason. and it isn't "low disign cost either"
.02
Round cables = FAD