I am running RDS on Windows Server 2008R2. No Remote App or Gateway Services, just straight up Remote Desktop.
After making a RDP connection to the server, when trying to access any SSL-secured website, Internet Explorer displays the error "Internet Explorer cannot display the webpage" with a button labeled "Diagnose Connection Problems." It's the same generic IE message that appears when DNS lookups fail. This failure to make SSL connections also manifests itself with Exchange autodiscover not working.
Strangely enough, Administrator is able to make SSL connections just fine, just not any other users. The server is otherwise completely functional.