Before you tear into the calipers you should definitely replace the flexible brake lines. As these get old they tend to swell internally and this can constrict the flow of brake fluid. Because you exert a great deal of pressure when you press the brake pedal the fluid has no trouble passing through the hose to the caliper. However, when you release the brakes there is no real counter pressure except for any slight out of round on the rotor to push the fluid back. This obviously means that your pads then drag and wear prematurely. Even a slight constriction of the flexible brake line is equivelant to you riding the brakes on that wheel. The brake lines are not expensive and if old should be replaced anyway. I'd say the chances are good that replacing them will fix your problem.

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold