Last Wednesday whilst driving our newly acquired 08 Roomster the interior lights came on and off with the car thinking that one of the doors was open. Looking though the forum(s) I concluded that the problem could be with the rear washer pipe leaking. However on Friday night after the car had spent most of the day on the drive I noticed that the hazard warning lights were flashing (the alarm sounder seems to have been disabled) and again the car thinks that a door was open. After a bit of messing around I came to the conclusion the problem is with the driver’s door.

 

Didn’t solve the problem and ended up leaving the car unlocked overnight. By the morning the problem had cleared up, on both days the weather was heavy drizzle. This does seem to be the switch in the door but could it be something else getting damp?   

A few of us on here have discovered the tailgate needs closing "firmly" in order to actuate the door switch:

 

http://www.briskoda.net/forums/topic/301759-help/?hl=%2Btailgate#entry3599807

Thanks, I did wonder about that but the boot light doesn't come on, at the same time as we are having these problems and I would have thought it would do if the tailgate lock was the problem?