Cannot save new panel layout while logged in as Admin

I've installed 1.0 beta 5 on Win XP Home XP 2 and I am using Firefox 2.0. While logged as Admin, when I change the page layout in Panel Wizard (for instance to a 3 columns), after I click the save button, I'm getting the message "panel saved properly" but nothing has changed. I'm still having the old layout in all pages.