I have a similar problem on Gutsy Gibbon (it was all right with Feisty and Edgy).
When I use any "shutdown button" :
o the little red botton on the task bar,
o the "System/Quit" menu,
o the desktop shutdown button,
gdm seems to freeze (the only thing I can do is to move the mouse on the screen) for several minutes (4 to 5)...
( ctrl-alt-F1/F7 works fine)
... and the the "popup shutdown window" came to the screen.
And effectively, if I cancel this"pop-up window", the next time I activate any shutdown button it works fine (the pop-up came immediately)
Version info :
-----------------
GDM 2.20.0
xorg : 1:7.2-5ubuntu13(gutsy)
I have a similar problem on Gutsy Gibbon (it was all right with Feisty and Edgy).
When I use any "shutdown button" :
o the little red botton on the task bar,
o the "System/Quit" menu,
o the desktop shutdown button,
gdm seems to freeze (the only thing I can do is to move the mouse on the screen) for several minutes (4 to 5)...
( ctrl-alt-F1/F7 works fine)
... and the the "popup shutdown window" came to the screen.
And effectively, if I cancel this"pop-up window", the next time I activate any shutdown button it works fine (the pop-up came immediately)
Version info : (gutsy)
-----------------
GDM 2.20.0
xorg : 1:7.2-5ubuntu13