Is this the default code, or your own program?
Have you followed the joystick zero calibration procedure?
Does it stop spinning if you jiggle the joystick just right?
If you write your own program, and set all the motor ports to zero, and the motor still spins, then the #29 is probably bad.
Just a tip: Posting questions for the general forum to help you with will often get you the information that you need and usually pretty quickly as there are tons of forum members online all the time. The replies that you get will also be from multiple members who may look at your question from different angles which will only give you a more complete answer.
Especially for some things that we all have dealt with at one point or another it can be frustrating seeing a question that you know the answer to or want to give your input on and then not being able to share what you know because the question is in the Official Answers only section.