Access Denied even though content type appears

I've followed the documentation and I've simplified my permission scheme to bare bones. An authenticated user only has forum and comment permissions by default. When he joins a group, he is granted rights to create story and page. This appears to transpire correctly under the create content option, as when the user is viewing the homepage, both story and page appears as expected. The problem occurs upon choosing to create content. He is hit with: "Access denied -You are not authorized to access this page." At which point he looses the links to create stories and pages. Clean URLs are enabled and I'm using 6.17. OG access control is installed, but not TAC or ACL. In fact, I've eliminated all access modules to narrow down the problem. Permissions have been rebuilt and all caches have been cleared. This appears to have been dealt with here: http://drupal.org/node/535738 but it dead ends without a satisfactory solution, as my Group Details block is already enabled. I'm not using any translation modules, but maybe something needs to be turned off? Could there be a dependency some where? I'm stumped.