my Munro was having that problem - at first i thought it was just burnt discs, but i use the same Cds and burn them the same way, and sometimes it does it, sometimes it doesnt. Threw in my new CD i bought from JB Hi-Fi and it started skipping - i freaked out thinking it was busting the CD...
took it to my dealer who happily ordered me a new head unit under warranty - until GM Holden said they weren't giving me a new one

- so they took mine out and are getting it "repaired" under warranty.
that was a month ago - and they called yesty saying it was back but cannot fit it again until the 16th - so i'll update you guys when it goes back in...