If you login using this page and it comes back saying "Login Successful" and the following page asks for a login once again, you are blocking this site's cookie. Likely causes are some sort of ad filter or proxy that is blocking your browser from accepting this site's cookie.
99% of all login issues we encounter are related to an issue with the web browser on the client side (that's you) of the connection. Please check your web browser, or try a different web browser before emailing us. If you have exhausted all options and still can't login, email us here.