Your key may not work in the lock because if you never use it the mechanism gets gummed up. Then the key won't turn (and for the person who asked how an electrical problem would affect the key, that isn't the problem I'm sure, it is mechanical). The locksmith told me to use WD-40 on the lock periodically and to use the key. He said don't use the graphite "lube" because it will clog things up by attracting junk.

 

I think you may be right, Jim. It's either what you said, or maybe I could have messed something up? I changed the door lock pins for the piston style chrome door lock pins. Maybe I accidentally pulled it out too much.