Hello!
I use Mandrake 10 (with some Cooker Packages) and I also have troubles with Nvidia drivers since I've upgraded to X.org
All Mesa/OpenGL programs now simply lead to a X server crash, also with gcc 3.4 I can't even re-run the nvidia installer (I have to downgrade to gcc 3.3 for it to complete its setup properly)
So I had to choose ... NVidia driver without Mesa, or Mesa without NVidia driver