Is it possible I have a defective USB drive? I purchased it from Long and McQuade, Cobourg. Should I bundle it and get an exchange? I can't even test it now.
Is the drive still under warranty? If so, consider getting it replaced.
Note that it's not uncommon for the internal drive to become disconnected from the data cable. Is the case openable to do a visual check to verify that everything is seated correctly? (Mind your warranty options).
Also, presumably you have rebooted the computer before checking again. I've seen cases where USB ports have become completely unresponsive, and its taken a reboot to resolve.