I did a little searching on Cable-Select setting, which is what lets the cable determine who's the master and who's the slave. I found a nice explanation
here.
Basically, to make cable select work, you need a special kind of cable, and most commercial ones out there aren't that kind. So the odds of finding a Cable-select environment on a new PC are pretty slim.
I'll go back to making sure that both drives are jumpered properly -- one as a master, and the other as a slave. The default setting for a drive is not to be jumpered as a master, so if you haven't fixed that, it won't work.
Ermmm... you *do* have the IDE cable plugged into the back of it as well, right?