Comment 14 for bug 282906

I agree - an upgrade to Intrepid has re-enabled the 'bell' or 'beep' when clicking 'Shutdown' or at the login screen. There is no way in the GUI or standarde Gnome settings to reset this (nonr that work, anyway). The only way to disable it again is:

run gconf-editor from terminal and set
/desktop/gnome/peripherals/keyboard/bell_mode
to 'off' rather than 'on'

Not exactly easy to find for your experienced users, impossible for the average user. At the very least this should setting should be migrated during an upgrade, but should really be editable from the Sound properties tab.