No one seems to have mentioned the big question here - do the tracks have the same problems and at the exact same spots each time you play them? (IE: Can you rewind and hear the same glitch?)

The drive cable is most likely, but it won't cause predictable repeatable errors. If, as you imply, your tracks were clean when uploaded and developed glitches while living on the hard drive, you've managed to do something very odd to them. It's also possible they always had the glitches, but your mp3 software on your computer dealt with the errors better.

Matthew