Yellow screen on 24" iMac

I've been aware of the yellow screens that have been plaguing the new 27" iMacs but didn't realize that the older macs (mine is '08) also have the same problem. About 1/3 of the left hand side of my screen is a blotchy yellow color and on the far right about an inch of yellow. The screen also has horizontal banding burned in. I have always had a screen saver active and the display turns off after 15 mins.

Is this likely to be a screen problem, or something that can be fixed using some software etc.?

Cheers.

Why don't you run this simple test and let us know the results:

Attach an external monitor to your iMac. Are you showing the same symptoms on the external monitor?

If yes, then it's likely a graphics processor problem. If no, it's probably the display itself that's defective. Is your machine covered by Apple care?

Regards.