I had the same thing happen to my WD Scorpio WD1600BEAS (Passport Original) junk drive. The USB adaptor somehow goes on the glitch (didn't rip off, nothing ever happend to the drive physically). Just quit working when I plugged it into another computer.
When you pull apart the mobile case and bypass the little card that adapts the HD to USB by using standard tech cables available all over the place (USB to SATA Converter Cable) the drive works fine.
Sub-standard electronics from Thailand...I bet tons of people pay big bucks sending these drives off to "data recovery specialists". What a joke. Western Digital should have a stock pile of these cards to send out to unhappy customers.