I have the same problem. (MSI K7N420 Pro, 1700MHz AthlonXP). Systems sounds work fine in gnome and kde. But games like Quake and TuxRacer have no sound at all. My /var/log/message file has errors about failing to find the char-major-13 module. If I put that alias into the modules.conf I then get errors about char-major-13-64 module not being there.
I've tried everything I can think of with the modules.conf.
alias sound-slot-0 nvaudio
#alias sound-slot-1 nvaudio
#alias char-major-13 nvaudio
Oddly, the system sounds work just the same regardless of what I put in there... I can remove all of it and just do a:
And everything works the same.... Puzzling.