Hmmm, this just sounds like an AD to me. Especially if you've only made 1 post.

It all depends on the severity of the scratch...if it is just a surface scratch on the plastic it can be buffed out rather easily with virtually any mild abrasive, although I suggest the scratch remover manufactured by 3M myself.

Scratches that penetrate the surface of the disc and actually reach the aluminum that carries the data, however, are a lost cuase, you might as well go purchase a new disc as no amount of buffing or no machine will remove the scratch. Also, be aware that it is not only the bottom side of discs you need be concerned with, as a scratch on the top can be just as harmful to your discs, however, usually the disc art on the top of most discs adds some protection not afforded the bottom of the disc.