[PROBLEM] It crashes.

Hello. I need help with a problem. My friend and I want to play Heroes WOG over the network, but there's a catch: the player who isn't the host keeps getting kicked out. When it's his turn, he gets kicked out of the game, and a message flashes on the screen (I can't tell you what it says because it flashes by too quickly).
Sorry if I haven't provided enough information; please help as much as you can, we really want to play.
My OS is Windows 7.
My friend's OS is Windows XP.