Ok guys, I am very sure that I have found the bitter bug that let some rigs sound very false when you load them once or twice.
I discovered, that this thing only affects rigs where I did change something in the cabinet, for example "low shift" or "high shift".
I tried this with different rigs and it happend to every rig I changed. When I set the Controllers to zero, everything is OK again.
So I think the bug is, that the controls of the cabinet are not loaded in the right way when you change from rig to another rig.
Sorry for my English, but I am German.
CHRISTOPH - PLEASE READ THIS AND GIVE ME AN ANSWER SOON!
Thanks!