This is an all to common problem and also made the site a little harder to get going then it should have been. There are 3 choices in the Teplate Chooser below the left side menu once logged in. Your choices are 800x600, 1024x768 or other. Other is designed for larger views.

 As long as your browser has cookies enabled then the site is set to remember your teplate choice for a good length of time.