MotoGP2 Trainers Problem

[Akumajo]

Does anybody know how to get unlimited credits with trainers for MotoGP2 to actually work? I can get my bike maxed out (50, 50, 50, 50), but it doesn't seem to have any effect when actually riding. And when I return to Redistribute Credits screen, it shows negative credits (-100, etc.). Is there some kind of built-in protection? Anybody know a workaround? I'm using NoCD crack too, if that makes any difference.