Edubuntu server: screen locks up on Quit

Running Edubuntu 7.04 server at home with one terminal. I use the screen for day to day tasks, and after I select System | Quit... athe screen locks up when I select any of the options presented, even Cancel. I tried logging onto the terminal, and although the login works, the system menus are not presented in the top panel. The only option is to use the power switch to restart the server.

I recently installed the kernel 2-6.20-16 upgrade.

Thanks in advance for any suggestions to resolve this.

John