Nexuiz does include a linux shell scripts nexuiz-linux-glx.sh and nexuiz-linux-sdl.sh which will take the right 32 or 64 bit variant and also take care of the right directory, use those to start the game.
A few lines down in this you can also find a link for scripts that also will do a simple autorecord.
Wich is the difference between the two (glx and sdl)?
Thanks.