Sedan Trunk Lock Stuck

[liseky]

I tried searching this but couldn't come up with anything so here goes!

My trunk won't open if I stick my key into it and try to turn. It does work if I pull the latch from inside the driver's area. I'm using my master key, same one I have always used with no problems until now. Basically, I'll stick the key in vertically and try to turn clockwise, but it won't budge. Every once in a while, or with slight wiggling it will budge and open. I have already used lock lube but that didn't help either.

Any help is greatly appreciated! Thanks!