The problem was with my side garage door causing locking problems. Though everything looked level and plumb there were some very slight tolerance differences. We took the strike plates off and cut the the nails holding the door frame to the rough opening. There were also two screws, one top and one bottom that were also removed from the strike side. The brick molding from the strike side and top were then removed allowing us to tap the top of the strike side in toward the garage and then tested the locking mechanisms for alignment and ease. Once in proper place, we secured the strike side top and bottom to hold it in place. When we had removed the brick molding we discovered that once the door was properly aligned, the sheathing on the strike side stuck out approximately a 1/4 inch. It became clear that the original contractor failed to square up the hinge side of the door opening with the strike side of the door opening thus there existed a slight torqueing of the door in the opening. With that, and the addition of cold and heat expansion and contraction, locking the door was problematic. We managed to trim down a 3/4 by 1/4 area of the sheathing so the brick mold would sit flat on the sheathing and door frame keeping the appropriate setback from the edge. We were also able to accomplish the work without affecting the siding at all. I had a piece of brick molding consistent with what was there so we were able to replace the strike side molding which I cut on my compound miter saw. Everything fit in perfectly and the door is easily closed and locked. What remains is some slight shimming, recaulking the top and strike side, and another coat of paint on the trim.