MP disconnect issue

[Brael]

I've been playing civ 4 with a friend of mine for years now and we've never had this issue. The game disconnects us both as soon as one of us enters the global view and then zooms back in from it. It has happened on three separate maps, but when loading previous games to try and narrow the problem down from the game to a map, it has worked. I'm out of ideas as to what could be causing it.