I have the same problem and dont want do reinstall.
the problem occurs, when clicking on "Sign up-Button" on the main admin-log-in page.
MESSAGE:
Fatal error: Call to a member function on a non-object in /is/htdocs/33721/www.artent.de/media/kernel/content/attribute_edit.php on line 78 Fatal error: eZ publish did not finish it's request
The execution of eZ publish was abruptly ended, the debug output is present below.