I have the same problem...
Happens on the second page as well. When you try to add a field it does nothing. Click try again, again, again etc etc eventually it works. But it only works for adding one field.. Close and open try again and again then eventually you'll get to add your second column (such as password). Then off to page three... Same problem, select to add, chose an available value to use as a session then it never completes...
CS5 latest stuff, 10 gigs of Ram, etc etc.. Yes' I'll now try removing the dat file