Password problem

I installed the latest version of Untangle on a PC, set it up using admin/admin as the username and password. It has been running for a few weeks and I have been able to log in from different workstations without a problem. However, after it was shut down and then restarted, a command line says:

Debian GNU/Linux 6.0 untangle tty1

untangle login:
(followed by) Password:

I have tried admin/admin but it does not accept it and I have tried all sorts of possibilities but no luck. I do not recall being asked to set up any other login during setup. Any ideas?

Thanks.