No event sounds - gnome 2.6 gentoo 2.6.7 AMD64

[Guy Rouillier <guy-rouillier speakeasy net>]

I'm new to gentoo but have been using gnome on Mandrake for years.  When
I startx, I hear the designated startup sound event; likewise, when I
logout of X, I hear the designated shutdown sound.  However, while I'm
using X, I get no sound for events.  I definitely have both checkboxes
checked (enable sound, enable sound for events.)  In the Desktop
Preferences - Sound applet, if I select the startup event and click
play, I hear nothing (even though I hear that tune at startup time.) 
I can use either aplay or esdplay on the same wav file and I hear
the tune fine.  I can also play music CDs (and hear them <gr>) using
alsaplayer.  I'm baffled - how can I get event sounds to play? 
Appreciate all suggestions.

One more tidbit - I have Mandrake 10.0 AMD64 on this same system
(eMachines M6805 laptop with Athlon64), which is kernel 2.6.3 and gnome
2.4, and everything works fine there.

-- 
Guy Rouillier