Not saying that this is your problem but I have, on occasion, discovered that I was pressing both the brake pedal and the gas pedal when braking, resulting in the symptoms that you describe. I drive our F25 very infrequently (it's my wife's car). Interestingly, we both had the same experience when we drove an X5 at the delivery center. (It was the first time either of us had been in an X5, much less driven one. We didn't know how to start the vechicle or select a gear. Made for some amusing moments.) Apparently the pedals are closer together and/or the seat is angled differently in the bimmer than in the old Fords I normally drive. My wife has totally adjusted since she refuses to drive the old cars! It has happened to me often enough that I now think about it as soon as I get behind the wheel of the X3.
Hope this helps!