I really doubt it's anything outside your computer or local network. The Telnet test you tried doesn't use the game in any way, it's a simple Windows function and if it's not letting you through, something's blocking or more accurately, not allowing it.
Did you run the Telnet test while connected via dialup too? If that also fails, it's nothing to do with your router and you can concentrate on your computer. Uninstall the Sygate firewall if you can reinstall it later. Don't rely on configuring or disabling it at this time.
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