I have a USB drive which used to work fine in one Vista SP2 machine but now isn't recoqnized (does acknowledge whenever it's connected but doesn't show up on the system devices info as a USB Mass Storage Device, as do the other USB drives when connected). Not too sure when it stopped working as I had the drive disconnected for a while. I've deleted the infcache.1 files but to no avail.

The system does recoqnize two other USB drives and the USB drive in question (with same cables/power supply) is recoqnized by my other Vista and another XP machine so I can rule cables out and the drive itself.