First, do you know if you have a virtual drive or not? I assume that when you copy the discs to your hard drive, you don't get any kind of read error, like a CRC error? Really sounds like a cd drive is going bad. You may check event viewer for any error message related to it. What's your OS? E-mail your dxdiag to me at
rchassereau@hotmail.com, and I'd be more than happy to take a look and see what's up.