Hey all, started having problems with the central locking on my mk1 focus, if the passenger side door is unlocked the drivers side won't lock using the remote it just locks and then bounces back open (Doesn't even appear to try lock the passenger side) yet if the passenger side is already locked then it locks fine. Does anyone know what could be causing this error?

I swear at some point i'm gonna forget and leave my car open thinking its locked, have to remember to watch for the indicators flashing!

Cheers!