Distorting and clipping on burned CDs

Question

I'm having problems with CDs that I've been burning. I've been making a lot of compilation CDs and haven't experienced problems before, but just recently I've noticed that a lot of the songs badly distort. These sound absolutely fine played from within itunes - it's when they are burned to a CD.
There is crackling, distortion and clipping at the top end which sounds horrible. I checked my itunes and the soundcheck and volume adjustment controls are disabled. The CD media is a good quality brand and the songs are ripped from CD (with error correction) or purchased from the iTMS.
iTunes is version 6.0.1 (3) with quicktime version 7.0.3. My mac is a revision B iMac G5 with a Matshita DVD-R UJ-845 superdrive (firmware rev DBN9). OS is 10.4.3
The song sources were in AIFF, mp3, apple lossless m4a and mpa and WAV formats. I checked the waveforms in Audacity for clipping but there was none in the original file. The CDs distort regardless of whether it's a cheap ghetto blaster, PC, Mac, stereo or home cinema system and the music ranges from hip-hop, dance and jazz to classical and acoustic. This seems to make no difference to the likelihood of distortion.
I've only noticed this problem going back to November.
G5 Dual 2.5

Answer 1

I am also having the same prob. I noticed though that
if I playback the burned CDs in my car, it sounds
okey. The ones I just burned from iTunes, if I play
it back within iTunes - they all have weird
distortions. So I guess it's a software bug not
hardware . . . then again, it could also be my
Superdrive . . .
Apollo
I was having the same problems, noise, noise and more noise right after I upgraded to iTunes 6. I checked in with my Mac consultant and she suggested I try repairing permissions. I did that and have had no problems since. I thought it was hardware based also, but I was wrong!
Here's what she sent me:
Here's how to repair permissions:
Open Applications > Utilities > Terminal
type this command:
sudo diskutil repairPermissions /
make sure there is a space before that slash
It will ask for your admin password
Good luck.
Brian
iMac   Mac OS X (10.4.2)