Clock still on after locking car?

[samsmeg]

Haven't been on here for a while but my friend has just bought an 02 plate 1.2 16v Clio Dynamique and has had a problem with his clock on the dash.

Basically it stays on after he turns the ignition off and takes the keys out then locks the car. He did just fit a different head unit but I have no idea if that is the problem and he can't remember if it did that before!

Any ideas?

Thanks

Sam