There could be a couple of reasons for this. If you are getting bad wavs, like hybrid suggested, then try slowing down your cd drive. Go into the settings tab, and there will be options for the cd drive, drive speed, and rip method. First, try slowing down the cd drive. If you have it set for 20x, try 8X. If that doesnt work, try changing the rip method to dynamic sync width or one of the fixed sync width options.

Sean