I downloaded a contrib "Better GUI ADMIN" from http://www.oscommerce.com/community/contributions,6731. Then I replace all the files in /home/admin with those provided in the contrib. I made the necessary changes in configure.php
I loggin at the http://my-site/admin webpage using administrator usr/passwd. Once I get in, I get a page with the oscommerce logo on top and the rest of the page empty with background color similar to #816106
Any help would be appreciated