CD-R and CD-RW

I have an '01 LS with the premium stereo (RDS tape and CD) it plays CD-R fine, occasionally it acts funny, but it won't play CD-RW at all. Can the dealer re-program the stereo with an update for this? Kinda disapointed in the features and great sound of this stereo and it won't play a CD-RW. Does anybody know the wattage? I wonder if I have aftermarket speakers, I bought this car used. It will vibrate the rearview mirror and sounds really good for a factory that isn't a BOSE or Monsoon.