Strange Electrical Problams

This is going to sound really strange but i have 2 problems. 1st is that the passengers door lock 'bounces'. I drive past 5mph and all the doors lock but straight away the passengers door unlocks itself. The 2nd problem is the speakers in the rear door. If i sit in the car with the engine running (all doors unlocked) the speakers in the rear doors dont work, as soon as i hit the lock button the speakers start to work. Hit unlock and they stop working. Its driving me round the bend because i can be driving down the road and for no reason at all the car will unlock its self then relock itself but the passengers door occasionally stays locked so the speakers work but when the passengers door lock bounces the speakers dont work.

Any ideas.