Ah, you're trying to load a saved game? You also need to make sure you're using the exact same AI War profile name as before then. If you try to connect with a different name and theres not a blank spot spot it won't connect you. Or have the host change the name in the Manage Players window to blank. Would suggest checking port forwarding or windows firewall, but you're doing this with hamachi so neither are probably bothering you.
The performance profile wouldn't hurt though. We tended to leave it at Normal or Low until slowdown made us lower it it in stages, since the guy with the strongest computer also had some sort of arcane multi-router setup that made it impossible to host but had no issue connecting to me.
