Try editing your tcadmin2_advanced.php in notepad. Find this line:
$code = '<form action="'.($params["serversecure"]=='on' ? 'https':'http').'://'.$params["serverhostname"].'/Interface/Base/Login.aspx?ReturnUrl=%2fInterface%2fBase%2fHome.aspx%3fGoToServiceBillingID%3d'.$params["accountid"].'" method="post" target="_blank">
Change it to:
$code = '<form action="http://'.$params["serverhostname"].'/Interface/Base/Login.aspx?ReturnUrl=%2fInterface%2fBase%2fHome.aspx%3fGoToServiceBillingID%3d'.$params["accountid"].'" method="post" target="_blank">