I have posted with the same question. Mine drag intermittently all the time. I am convinced that this is what caused me to warp my rotors. With the front wheel in the air, I can 'spin' the front wheel about one quarter of a turn. I can hear them while I am riding. I have flushed the fluid (this helped for a while), but now they are doing it again. I ride my bike year round, so this isn't from sitting.
I have taken it to the dealer twice, and both times they don't notice or hear anything. I want to take the calipers apart, but I'm afraid if I do that, I will get blamed if there turns out to be something.