The alarm on my p1 V70 T5 is going off more and more for no apparent reason. What I have noticed is that after it has gone off, one of the rear doors, even though fully closed, has the door open red light lit up.

I can only think that the car thinks the rear door has been opened even though it hasn't, but why is the door open light coming on when the door is fully shut?

I've just tryed turning the child doorlock on, but the alarm still went off, and I want to go to bed!

Help.......please!