This is really weird. I just upgraded my HDD and restored my computer from a Time Machine back up. Everything works fine, except my interface sounds! Other sounds work: iTunes, internet sites like YouTube, VLC, etc. I've already gone into System Preferences --> Sound and made sure everything is enabled, but I still get no sound from stuff like emptying the trash, moving files/folders, etc. When I hit the Volume Up/Down buttons on the keyboard it does display the bezel and make the beep. Does anybody know what the problem is and how to fix it? Thanks very much!