Access Denied to Admin pages when logged in as uid=1

I have a site that was working fine. I was configuring the site, nothing special, just some content creation if I remember correctly and now I can't access any of the admin pages. I'm logged in as my uid 1 but if I try to get to any page under admin/ I get an access denied message.

PHP5, MySQL5, Ubuntu Server 9.04, Apache2.