Yeah, what Andy has posted would be the first thing to do.
If for some reason you want 3123, or if you want to compile from source for some other reason, then you can put in your Mandrake CD 1, reboot to the Mandrake installer, go through it but make sure you select upgrade instead of install when asked, select "development" on the first package selection screen, and let it continue on through where it copies files, and then exit it, you should get a compiler installed. After that's done, make sure CD 1 isn't in the drive, and reboot back to Linux. Then retry the cc -v, and you should get "gcc version 3.2" printed.
If you do, then restart the nVidia drivers. However, as I said earlier, the binary RPMs for 4191 should work if you would rather go that route.