I have a problem in which it appears that I can't get the parking brake to release (or the brakes are stuck on).  I'm running P3D V4 and using FSUIPC.  Everything seems to work correctly in the cockpit, but when I view the aircraft from the outside I get smoke and sparks when I taxi.  My understanding from other threads is that when I set/release the parking brake I should see the rudder pedals move, but they don't.  The parking brake appears to work correctly in the cockpit (i.e., the keyboard command works properly). I've tried everything I can think of to fix the problem, but have run out of ideas.  Any suggestions would be appreciated.  Thanks. 

Have you aborted a gsx push back? I didn't look for smoke and sparks but I wasnt able to taxi when I aborted the push due to a messed up parking spot...

Common problem is many controllers require that the brake axis be reversed.  Try it.