Many virtual environments and hosted platforms only assign private IPs to server network interfaces, and use a "floating" public IP for external access. ThinLinc's 'agent_hostname' variable will default to this private IP if not set, which causes external ThinLinc connections to fail, and is difficult for new users to diagnose. One option could be to prompt for the server hostname or IP address during installation, and set this value accordingly if given.
*** This bug has been marked as a duplicate of bug 6144 ***