I've been wanting to jump into the Mac scene for awhile now, and these new iMacs are exactly the excuse I've been needing to force myself to do it. An iMac with a dual-core Intel chip? Man, two years ago that would have been unthinkable.
Seen it a lot. My first suggestion, take to another PC and try it on a few other CD-roms. I expect the disks are CD-RW disks - right? The burn is not as deep as CD-Rs. I hardly ever CD-RW disks ( have a jump drive for re-writable data).