What would cause this problem.

Power door locks will lock from the inside switch on driver and passenger side but won't unlock. Put the key (and turn it) in the hatch lock and it will lock or unlock all locks. Put the key in the passenger side door and it will only unlock the passenger door. Drivers door the key won't even unlock or lock it.

 

Bump, trying to help my brother out.

 

What's the exact issue here again? the power lock(s) or the manual lock using the key from the outside?

 

Sounds like a rod could have come loose on the drivers side. Have you opened it up and looked.