This is an issue with the firewall settings for the network the customer is currently on. To test the network, do the following:
1. Start command prompt in Windows XP by clicking Start -> Run and typing cmd.
2. In the command prompt type the following: telnet itsnt375.iowa.uiowa.edu 1494
3. If a firewall is blocking the connection the command prompt will say "Connecting to itsnt375.iowa.uiowa.edu" and after 10 seconds or so, "Could not open connection to the host on port 1494: Connect failed"
4. If a firewall is not blocking the connection the screen should just say "ICA"
If you find that a firewall is blocking the connection, you will need to check the firewall and antivirus settings on the machine to see if there is any way to allow this connection through. You may need to contact the network administrator to see if they are blocking this type of outgoing traffic.