Dapper upgrade hangs - what to do?

[jean-ooo at taming-openoffice-org.com]

Daniel Carrera <daniel.carrera at zmsl.com> wrote:

> 1. Close the upgrade manager. Cancel the process.

Hmmm... I can't find how to do cancel the process. :-( I am on a window 
titled "Upgrading Ubuntu", which has no "Cancel" button and no "X" in 
the upper-right corner.

Can someone tell me how to cancel or quit out of this? Obviously one is 
not supposed to stop in the middle, and in fact before I started the 
upgrade process there was a helpful notice saying (paraphrased): "Do 
you really want to do this? It may take several hours, and you can't 
stop it once you start it."

Cheers, Jean