Locking issue on Ford Focus year 2000?

Very similar to most of these issues. When I try to lock the car with the key phob, it locks then unlocks straight away. If I lock the drivers door with the key(old fashioned way) I can then use the key phob to lock eveything else. Also same as most people, when driving i get the sound of the locks trying to open...
Ive tried the turn key4 times...and spraying the locks, but to no avail....can any help please.

Gary
March 2010