Start up a terminal: i.e. xterm
Enter the following:
This should give you the actual version of your kernel. I'm not familiar, however, with Mandriva. But it looks like from your log file you do have your source files installed. This would definitely have to be the case if you were able to run the NVIDIA-Linux-x86-1.0-9629-pkg1.run file and succeed in compiling the nvidia.ko module.
But Linux is not like Windows. You do have to a little bit of research. But it sure is more dependable. You need to do some research, perhaps on a Mandriva forum (or just read the documentation), on how to install the correct headers for your running kernel.
It appears that you have the headers and source files installed for your distribution: they just don't happen to match your kernel. They have to match exactly. If you can't find a matching set of headers in your distribution that matches with your running kernel, then see if you can't find a matching kernel that coincides with your currently installed headers.