I had WP 3.1.4 and PHP 5.2.17 running fine.
The upcoming WP 3.2 requires PHP 5.2.4 so I asked my web host to upgrade PHP.
Now I can't get to my WP Admin page.
I'm using Safari so I tried FireFox and can't even log in there.
Something's wrong with WP.
Frankly, there should be more graceful backward compatibility.