When I visit the login page and attempt to login with the supplied username and password I see this at the end of the URL:
This tells me that it is failing the access check on the index page. This access check should be based on the rules applied to the page and the values that are held in the wa_settings table in your db. Did you have a previous PowerCMS installed on the server or any other solutions that have an installer? If so the username and password you set during the install might not be the correct ones to access the pages. You can check on this by viewing the wa_settings table in the db. You should see the username and password here. If you can't get in with these values post back and let us know so we can look into this further with you.