If you add nvidia to /etc/modules, you do not need any alias in modules.conf.
However, if you have anything in modules.conf, it should not be char-major-195. char-major-195 is for systems that do not run devfs, and Mandrake 8.1 definitely does use it. The /dev/nvidia* alias that was there is right. Use it if you use anything.
However, as far as lsmod goes, is it showing an (unused) after the module, or does it just not list anything using it? My NVdriver (I'm still on 3123 -- 4191 has missing symbol issues in libGLcore on my system) isn't used by any other modules, but it doesn't say (unused). If yours does, you should probably post your XF86Config-4 file.