On Mozilla 1.2Beta (mozilla-1.2b-0_rh8_xft.i386.rpm, etc.), attempting to exit the Preferences menu for Mail & Newsgroups -> Notifications without clicking on "OK" or "Cancel", e.g., clicking on a different preferences sub-menu, locks Mozilla hard, that is, no Mozilla processes respond to any user input.
Works for me, build ID 20030226 on linux. Scott, can you reproduce this with a current copy of mozilla? If so, could you try creating a new profile and see if the problem appears while running under that profile? To create a new profile, launch mozilla with the "-ProfileManager". How do you have the controls set on this preferences pane? Are you trying to turn on sounds when mozilla locks up?
I no longer see the bug either, since mozilla-1.2.1-0_rh8_xft.
vrfy per reporter.