Today, the door open warning light on the dash display refuses to go out. All doors shut properly, boot and bonnet included. I can't lock the doors: double clunk when I press the key fob.

Megane 1.5DCi, 55 plate. Just finished resolving a clutch problem and now this.

Any ideas, anyone? Can I hook up a laptop and diagnose this problem, or do I have to go to garage?
Now on the lookout for a Nissan Juke. (Another funky-ass fun car)
Cheers
Ian