I have the same problem. To add more information my WHS 2011 is behind firewall which has UPnP enabled and WHS was able to configure it properly. My router was previously bound to dyndns.org domain and to get proper certificate from MS I have removed this
DynDNS domain from my account and from the router. This has been done a few days ago, WHS shows that RemoteWeb access is working fine but I still can't access my server from the web.