Lots of drives don't seem to measure their own power supply... That means if you run them on a laptop with a slightly out of spec power supply, you can get the drive marking hundreds of bad sectors, yet when you put them in another machine they're fine again.

If you're designing something as complex as a drive, you would have thought they'd have a bit of electronics to test the power supply and refuse to work (with some relevant error code) if it's out of spec.