The hotfix associated with KB2897602, "TCP connections that use ephemeral loopback addresses are dropped suddenly in Windows", has fixed my Windows 8 RDP client freeze problems.
Symptoms
You run an application that connects remotely by using a TCP connection on a computer that's running Windows 8, Windows 8.1, Windows Server 2012, or Windows Server 2012 R2. If the TCP connection uses ephemeral (short-lived) loopback addresses, the connection may be dropped suddenly after 40 to 50 seconds. However, the TCP connection is still "live" from the client side. In this situation, the application does not maintain the remote connection.