Thanks for all the replies guys, your stars..
The car is still under warranty for another year I think so I might get it sorted via them, bit annoying that a 2 year old Z has this problem, yet like you guys say after its warmed up no problem at all with the CDs (it is the 6 CD Changing unit I have)... I have taken the CD's out on a morning and there is no condensation or "misting" on them so was a bit miffed...
Might as well get it re-gassed at the stealers whilst its there as long as its not more than £50..