Okay, so, I've had this game for a while, and although I've never played online, I've enjoyed it.  When my friend got it and installed it on his computer, we decided to try a couple LAN games together.  Now, on my laptop, I can host it fine.  However, he can't see it.  We had the same issue with Warcraft 3, though the opposite way around, so we decided to switch roles.  The problem lies herein.  When he attempts to host, he gets an immediate Network Error: Disconnected from Game Server.

So, how do I fix this?  I'm sure its been asked before, but I don't really feel like digging through 58 pages of technical to find a solution most likely buried in other problems.