Trouble with Stock CD Player

Hi.. anybody experience this? Every once in awhile the CD player won't take the CD. Sometimes it's a CD-R sometimes it's a store bought CD. The unit will pull in the CD.. but will never play the disc. I can hear the rollers spinning (like it doesn't see the CD) and after like 20 seconds it will spit out the disc. If I keep trying.. eventually it will take it and start playing.

Is that something that I can have fixed under warranty? Or do I just need to clean the CD player somehow?

I have a 2004 (non JBL) with about 30k on it.

thanks so much,

Peter B