HELP

me and my friend were trying to play sin of a solar empire:diplomacy yesterday and encountered a problem. when either of us tryed to enter a game  hosted by the other its said that our mesh files weren't installed right or something. well we thought must be a new patch. after trying to update we checked and did have the most current editions of all three games. we decided to uninstall sins completely and reinstall. after checking and failing horribly we still cant join an online game with each other. if any one has encountered this problem before please respond to this post or email me at [email protected]. guesses and ideas are also welcome. on another note if i voilated any forum rules i apologise. i usally just lurk on forums.