David,

it seems to take longer than it should for
the shutdown window to show up

The shutdown dialog should pop up almost instantly, but the shutdown process
itself could take a while (for instance, when trying to reach remote
resources - drives on another computer).

I've never heard of the popup dialog itself taking a long time to appear
though, and no idea (other than wild guesses) to what could be causing it.

Regards,
Rudy Wieser