Citroen picasso door saying open when it isn't ?

[RachelPashby]

My citroën dash is saying that front and rear doors are open when there not. Normally I wouldn't care about that kind of thing but as a result my car won't lock! I put the key in, turn it, the door locks and then re opens, usually a good sign that one of the doors is ajar. Also the warning is constantly on so I can't see other things like outside temp etc. There are no plungers like some cars so I'm guessing it's all an electrical fault, I took both electrical connections off and dried them and cleaned them but it did nothing. Is this a common fault? Cheers.