Having bought our PS3 60GB only yesterday, my 10yr old son played Lego Star Wars successfully for a couple of hours until the colours on the screen started to break up. Colours come out of the characters like giant spikes making the game unplayable and I'm at a loss at how to return it to its previous playable state. Restarting and cleaning don't help; our other games (FIFA08, Motorstorm, Dirt) all work OK.

Any ideas?