Top left/right buttons on steering wheel are programmed to the far left/right red buttons on shifter and vice versa. According to Kaz tweet the bug is fixed and will be patched in the next update.
Was going to post about this, just tried to remap the wheel and having the same problem.
Surely PD would test functions before they released the update?????????? Getting tired of problems with GT5 now, trying to stick by it but this is poor and puts a bit of a downer on the update.
