Everythings fine now. Got the solution over your idea, even if it was not the solution. When you update kernel and kernel-source (as me to 2.4.20SuSE-100) we should read the NVIDIA-HowTo on Suse homepage under
As you read there, you have to 'configure' the kernel source by executing
make cloneconfig && make dep and export IGNORE_CC_MISMATCH=YES.
After that everything runs fine.
But I?ver learned a lot
Maybe it works for you, too!