Can't login from restricted pages

No users are able to login from restricted pages, even if they are authorized to view the particular page.

For example, I, as an dministrator should have access to the page: http://www.odessapage.com/new/admin/node after logging in. I am able to log in from an unrestricted page, such as http://www.odessapage.com/new/ and navigate to admin/node, however, if I attempt to login using the login box on the admin/node page directly, I will get the infamous "Access denied
You are not authorized to access this page." message and will not be logged in, as if I entered the wrong password.

Is this a known bug with a known fix? I have not been able to find an answer among the many login problem threads.