A while back I got out an old P3/850 I had built but never used much. I'd always had a nagging problem I could never track down - when burning a disk, sometimes the verification step would fail. I tried everything - master/slave settings, new cables, etc.
The computer had two drives - st340016a and st340014a - almost the same drive. One was the "os drive" and the other a "data drive'

Fast forward - the battery had gone bad, and all cmos settings lost. In the process of fixing it back up, I swapped the drives around and reinstalled windows. Now it was booting off the other drive. Suddenly I was having all kinds of problems - registry errors, programs failing to load, etc.

I swapped the drives again, reinstalled again, and problem solved. So that drive was rather violently introduced to the sidewalk before being tossed.

Here's the part I don't get - that drive had passed scandisk and seatools. Is the moral of the story that those tests are not infallible?