Unable to connect via Remote Web Workplace SBS2003

Have been having problems lately connecting to a remote computer via RWW. I receive a logon prompt but once I have entered my credentials it just sits there and then eventually times out. I have restarted the client PC but still having problems. I have also tried logging into the local server and running an RDP connection to the client PC but this also has the same problem. Looks like the problem is with a setting on the client PC but am unsure of where to start looking.