after restart gnome sth wrong about the panel...
 

Everything went well after i install Debian Etch and i configure sources.list and apt-get update &apt-get upgrade .until now, everything is smooth. however,after i apt-get install audacious, i restart gnome(ctr+alt+baqckspace) there's a warning window saying "I've detected a panel already running and now will exit "and top and bottom panels disappeared .I guess the panel thread has running but why the panel can't be shown?

Try
This happens because Ctrl-Alt-Backspace is the rude way to restart X. This should really only be used in errors. Try logging out next time.