Can't get to the Admin panel
 

I installed PHPBB2 and then Photopost - my cookies etc are all correct. However when I try to login to the admin panel adm-index.php - I log in and it takes me to the main photopost screen - photopost/index.php.
Also when I log into phpBB2 - I cannot login it continually prompts for my login details when I go to the Admin panel.
I've reinstalled everything from scratch - and can't figure out what's wrong.
My gallery is at http://www.shopho.com/digitaloish/photopost - Forum is at http://www.shopho.com/digitaloish/phpBB2.

Please assist.

Many thanks.