invisible disc

[John Lowther]

hi, 1st of all this is not Tracey Gagne writing in on the blue screen 
infinity thread. Instead is the owner of this account, John Lowther.

i just inserted a data CD. it has some word files on it and some jpeg 
image files. when i insert, the machine whirs into action as usual but 
no disc appears on the desktop and looking in the finder shows nothing. 
  i glanced in iTunes to see if it was treating it as a music CD but 
that isnt the case (plus i know it would still have shown in the 
finder).  i've inserted other discs, they all behave normally.  others 
have used and accessed the info on this disc from other computers and 
so i'm perplexed.

any suggestions?

My system is an iMac 17' flatscreen
running OS 10.2
768 MB
800 MHz
PowerPC G4