brake caliper frozen

My right front brake caliper is frozen and I cannot turn the tire. This happened about a month ago and I went to Autozone and they gave me a new caliper, rotor and brakes, under warranty, and now the caliper is frozen again and I cannot turn the tire when jacked up. It seems to release after a period of time. Any ideas of where I should begin? I am not sure if it has a proportioning valve for the front brakes, but the driver side wheel turns freely and is not stuck.

Replace the brake "flex" hose, the rubber hose that runs to the caliper. It probably is coming apart internally and acting as a one way valve not allowing release of brake pressure.

I'll second the flex hose.