Comment 4 for bug 451160

About "Add" button in the "Add Rule" window:
"Add Rule" window isn't a modal window. It will visible always (if you click "Add..." in main window), and you can change the properties in main window simultaneusly.
It's as Gimp mode, you have 2 windows simultaneusly.
But you can close the "Add Rule" window if you push the "Close" button in "Add Rule" window.

In other way, if you need/like run the last version of Gufw, you can exec in terminal:
bzr branch lp:gui-ufw/gufw-10.04
cd gufw-10.04
sudo python gufw --dev

You can add or change the firewall as if Gufw will be installed.
When you finished, remove the gufw-10.04 directory ;)

Thanks and best regards!