door locking

Does the door sag at all? A worn hinge pin might be putting too much pressure on the latch. Might also be a the door lock actuator dying.

Door alignment does not affect the locking mechanism and its associated electronics. These are all things that are happening inside the door. Checking fuses is a good first step. There is also a body receiver for the entire car located just below the windshield. They eventually give out and the problem of locking and unlocking gradually gets worse and worse until it stops working altogether. I would think that would affect all doors equally though, but its worth bearing in mind. Unfortunately due to the required reprogramming getting it replaced is usually a trip to the dealer and won't be cheap; If you don't want to spend money on it make sure the key assemblies to your door locks are in good working order in case you have to revert back to the days of the pilgrims and use a key. I speak from experience after I got totally locked out of my Cobalt and had to call a tow truck to get me in again.