Dragging rear brake (revisited)

[Am_Dew]

A little over 4 months ago I took my '05 XLT back to the dealer I bought it used from because the right rear brake was occaisionally dragging while starting out or very slowly creeping in traffic or at a stop light. They said they did not find anything wrong and replaced both rear pads and rotors.

http://www.explorerforum.com/forums/showthread.php?t=160377

All was well for a little while then it started happening again. Last week I took it back to them and this time they replaced the pads, sanded the rotors and also replaced the caliper on the right rear thinking that it must be defective. Well, since then I have heard the right rear brake dragging again twice, each time when I first started off after not driving the vehicle for a bit...ie. first thing this morning. I only hear that brake dragging when I am starting out and once I get above about 10 mph, the dragging noise stops.

Since they replaced the caliper and the dragging continues, what else could be wrong?

 

[tower]

E-Brake?

 

[Am_Dew]

I rarely use the E-Brake and it was not on previous to the two times I've heard the dragging since the caliper was replaced.