power locks

I own a 99 civic.  Tonight I unlocked the car as usual with my car remote.  After unlocking the car, I got in, closed the door and proceeded to lock the car manually through the power lock switch.  I realized that my drivers door did not lock.  Only the passenger door locked.  I turned off the car and tried to lock and unlock the car with the car remote and the same thing happened.  I've never had this problem before, so I do not know if it has something to do with the power locks or the alarm by its self.  What is strange, is that the passenger car door locks and unlocks perfectly with the car remote, but the driver's side door does not.  If anyone has had this problem before or could help advise me on how to solve this problem, it would be greatly appreciated. Thank you in advance.

George

 Is the locking after market or factory, and if the system is factory but did not come out with keyless entry it may have a drivers door solanoid added and note if you did try to opperate the system with the drivers door open ( not latched ) this could have cuased the knuckel to come loose on the door lock rod. ( remove drivers door trim and investigate )

Thanks for the info guys,

However, the door was closed when i tried to operate the system both manually and via the remote. However, my bro sometimes uses the car and likes playing around with the alarm system. Since my car has vertical doors installed, he like activated the alarm while the door are open. This in turn would lead to the knuckel becoming lose. I'll check on it this weekend and try to figure out what the problem is. Also, assuming the knuckel came loose, are you still suppose to hear the sound of the door unlocking and locking. If you are then the problem is something else because you are only able to hear the sound of locking and unlocking on the passenger side door and not thr driver's side. The drivers side door makes no sound at all. Oh yeah, the power locks system is factory and the car was made for a keyless entry sytem however i did'nt purschase that feature from the dealer, i simply purchased on alarm and tapped into the wires at the keyless entry system.

Thanks again, George