'05 Base Parking Brake Cable

I have an '05 Mustang Base, V6 with a 5-speed. In the last 14 months I have gone through 4 parking brake cables. In all cases they seized up while holding the brake on. I have had to remove the tire and pry the cable off the caliper to get the car moving. The first time was shortly after rotator cuff surgery at a followu-up appointment. Seized AFTER driving 50 miles when i set the brake at the doc's office. That was fun.
But that seems like an extrordinary large amount of cable failures. (Currently waiting for rockauto to ship a replacement. This one only lasted 5 weeks!! At least it's free.) So what in the world could i be doing to cause the cables to seize. The all come pre-lubricated so i have not been adding any. In all cases, even when I remove the cable i cannot free the cable from the jacket; seized up tight. Any ideas what could be causing this?? PITA to keep having to pop a cable off in parking lots...

I'm guessing something is making/letting the cables untwist, thus making a larger diameter. After connecting to the pedal end, just before sliding into the backer plate try to twist the cable to make it tighter (smaller diameter) before connecting to the brake pull lever. Then after several uses, take it off at that back end and see if it can be tightened anymore after stretching. Don't go all Hulk on it, just twist to get any slack out. That's what I'd do if you don't see anywhere on the old ones where something is being pulled into the sleeve at either end to cause the locking.