I have exactly the same problem with my 2000 323i. The key works sporadically and only opens the driver's side sometimes. The lock and trunk work fine. What my workaround sometimes is to press the lock button and try unlocking it again. Sometimes doing this a few times works, otherwise, get into your car, turn the ignition on, even start the car if necessary and then hit the central lock. This usually always works. It's still a little embarrassing but I've never had to have someone climb in through the driver side. Has anyone asked the dealer to reprogram it???