Running version 18.104.22.1681. We are using ldap.ora; I can tell that my oracle client configuration is good because I can use tnsping to successfully connect to the database. The only variable, really, is that I recently switched to a new machine with Windows 7. When I try to log in to the database, I immediately get an error popup (red X with "OK" button) but no text -- totally blank. And I'm not logged in. Can't log in after that, either. I've put my oracle_home in explicitly, too. Not sure what's happening, any thoughts? Thanks!