PsychoCat, the same thing happened to me. I bought the IOMagic drive at Staples (the day after thanksgiving). I thought that i was getting a BenQ 1620, but it was the BTC drive instead. After doing a lot of research, I returned the BTC drive and bought the OEM BenQ from Newegg for $69 + $5 S/H.
Since then I have been really happy with the BenQ. The few extra dollars spent was well worth it to me. There is a lot of information on this forum about this issue. Search/Read some of the threads starting from the day after thanksgiving.