I am not quite sure if I interpreted your question rigth. If you were
talking about leaving (logging off) Gnome you should select the menu
"Aktionen" aside "Anwendungen" and use "Abmelden" (I suppose your are
using a German Gnome).
If it's halting or rebooting the entire system you're talking about
Please one question: "Do i have any chance to run down the machine as a
normal user i am (in front of X), i mean "Gnome-Desktop", cause i havn't
found any icon in the menu bar for 'shutting' the computer.
My startup goes over the console, think runlevel 3, and then after given
"