What have you tried to get the drive to work?
I briefly owned this drive (returned it because the extra cost, imo, didn't justify the minor speed boost over the internal drive), and had no issues with it in regards to compatibility. I just plugged in the y-USB connector into two available USB ports and disk utility recognized it within a couple of seconds. Do you have enough bus power available to power the drive? I know that if I tried plugging both the optical and my portable HDD, that one of them wouldn't power up all the way and thus not be recognized by OSX.
You shouldn't need to install any software for this drive to work. I believe the Windows CD comes with DVD playback software, not drivers (although I could be wrong there).
Bear in mind that OSX won't display the drive on your desktop unless there's a CD/DVD inside the drive. If you haven't, check disk utility to see if it displays the drive when plugged in. To check that the drive is indeed receiving enough power from the computer, try opening the drive tray via the button (not the little emergency hole on the drive). If it pops open, then I don't think it's a power issue...