From site's staff on their Facebook page:

A tip to fix one of the issues that people who managed to log in via the email reset function...some of you have been reporting that they are able to log on, but have to reset repeatedly....this is from one of our members:

"After the first login, your email address will likely default as your user name in your browser. Change that to your user name for the site"

Once your browser has saved the log in correctly then there should be no problem