the link you provide in your initial post goes to a 404 page not found error.
If the login is not working, the first thing to check is that the server is properly configured to save session information.
Use the session test page from the following thread to test the servers session management:
if the session test fails, you will need to contact the host to have them correct the issue, most likely it is a bad session.save_path in the php.ini file.
What are the errors you are getting? can you please explain in as much detail the nature of the problem of you are having? without knowing the specifics of the issues you are experiencing, it is very difficult to offer an answer or suggest a fix.
It would be better if you start a new thread with your issue to limit confusion in this thread so I can address StephenMartin's problem. I will address your issues in the thread that you create.