CD's and MP3's skip on playback

I bought a new CD and put it into my iMac, and it began skipping immediately on playback. I thought the disc may be scratched, so I ejected the disc and it looked normal. I put it back in and it skipped again. I thought maybe the drive had a problem since I have several unresolved problems with this dvd drive, so I took it to my car and it played fine. I then played it on a Windows PC, and again it played fine. Put it back into the iMac, and it skipped again.

Here's the strange part: I ripped the CD on the Windows PC, went to the Mac and navigated to the MP3 files via Finder over my network, and when I played them they skipped again! They skipped when playing via QuickLook in Finder and via Quicktime.

So since the MP3 files skipped on playback, that implies something other than the DVD drive. Has anyone else had this problem?