peugeot expert 1.9 d2005 van - central locking - westport44

Hi.the passenger door wont lock with the remote.if i lock the passenger door manually all doors will lock.if i use the remote all doors will open &lock normallyexcept the passenger door,it will stay locked.If i unlock the passenger door no other door will lock with remote until i lock the passengers door.Has anybody encounteret this problem,I would be grateful for any sugestions. westport44