Freecom External Hard Drive and Mac

I recently got a 160GB Freecom "Tough Drive" for my iTunes music and photos, which were taking up all the space on my Mac iBook G4. I transfered all the files no problem, and can play them through iTunes. But every time my computer goes to sleep, and often sporadically, I get a "device removal error," and the computer tells me that I may loose information if I don't do so correctly. Then I have to wait several minutes for the computer to recognize that it is indeed still connected through the USB. I usually can't use iTunes for more that 20 or 30 minutes without the hard drive (or the computer - I'm not sure which one is the culprit) randomly crapping out on me. Help! Anyone! I love my hard drive, but I think I'd like it better if it actually worked properly.....

 

Freecom informed me that it was a power-related issue, and I purchased the appropriate power adapter. However, now the thing DOESN'T WORK AT ALL! My iBook doesn't detect the device in the USB port, and when I tried it on two different PC's, it warned me that the device had exceeded the power limits of the hub. ANY SUGGESTIONS?