[zacut]

For anyone who is interested. . .

I found a gm mechanic on line who shared a service bulletin with me for 99-05 gm vehicles. It stated that the lock cylinders are prone to collecting enough of a dust build up to impede the pins from retracting correctly. The recommended solution was to shoot 60 psi of compressed air or brake cleaner in the lock cylinder to dislodge the material. It sounded far fetched after all I had tried but I gave some brake cleaner a shot and problem solved. I think I will remove the lock cylinder and clean it thoroughly and then oil it with some light oil.