Philips 6000CD from Mondeo - Error 15?

Hi,

I have a very annoying 'Error 15' code come up on a regular basis and I can only listen to the CD for about 5 seconds before the error raises its ugly head. I have looked in the manual, which shows some codes, but not this one. I am close to the edge and I am begining to loose the will to live - get my drift!
I would be hugely appreciative if anyone could give me an idea of what might be wrong?

Kind regards

Chris