drivers door lock/unlock not responding to key fob

[BMW DIY Guy]

Hey yall:

I have a mystery that cropped up yesterday as suddenly the lock/unlock from the key fob is acting strangely. This doesn't appear to be the atrocious fob range issue or low battery in the key, like I have in my E46 M3, as the range on this key is like 30 yards or more.

Starting yesterday, suddenly the drivers side lock doesn't respond to the lock and unlock commands from the fob. The rest of the doors do, the interior lights come off or on as appropriate, the red security blinky works etc etc.

When I lock everything secures normally, except the drivers door will be unlocked and if I pull it open nothing else happens like normal, such as the interior lights coming on etc. The car THINKS it is locked clearly. Manual lock with the key in the door works fine, the lock plunger will go up and down normally, and the door will lock.

I *think* I saw this behavior once a couple of weeks ago, but just once but enough to go huh, what was that, but then it worked normally. Why time is important is the only thing that has changed in the last weeks is I pulled all of the door cards to replace all of the speakers with the BavSound S1 kit. (that diy is pending and will be posted here!)

So I COULD have influenced this behavior when I pulled the door cards, but I really don't think so. Its winter but nothing is frozen up so I don't see tempuature effecting this whatsoever, especially with all of the frozen lock issues I read about.

Ideas? Suggestions? Places to start? This is something I haven't ever had to deal with so no clue of where to start.

Thanks!