If the installation does not choose at least one of the offered "Make your basic firewall settings" (access to Web surfing, e-mail services, for example, or VPN services, protocols) later in the firewall rules there is no tab to add ruls. Please let someone check on the new initial installation and do not let anything as permitted
Looks like this is the same IE8-glitch as the one described here, which we track as Mantis ID #20533. Can you please re-check this with the next beta and report back if it works?