Went out to my car at about 11 last night and the door wouldn't open, the handle feels normal but door felt stuck. I figured it was iced closed so tried the pasenger door, which opened normally. Thought it would need a push from inside, but it opened fine. Any ideas? I am thinking the lock maybe froze up, but the pin on door was up. Anything I can do to free it off? Its the same this morning.