Originally Posted by imag

One of the brake guys should correct me if I'm off, but my immediate thoughts was pad deposits on the rotors. If you got them heated up, then stopped in one place with the brakes on for a bit, or put the parking brake on for a bit, that would do it.

You can get the rotors resurfaced. Any brake shop and even most mechanics can do it. And don't let someone try to make you think you need a whole new set of rotors.

If you have abrasive pads (HP+), it's possible you can repeat the bed-in procedure to remove the deposits. If you don't know how to do this, I recommend resurfacing.