I can't play a game i saved in coop

Everything works great until the game map appear.
The game freeze, i have the ToS mouse, but nothing is clickable, there's no music, ... when the game was saved, that was my turn. When the game is loaded, this is my turn, but frozen.
When the server is closed with a "terminate program", there's a message on my screen: "Connection Lost..."
What i have done to load the game:
-Launch a first Tos (server)
-create game
-Launch a second ToS (my client)
-join game with my IP
-My friend launch ToS on his computer
-join my game with my IP
-I click accept
-i choose my save game
-As soon as i click, the game beginned
-the map appaired on the 3 ToS
-everything frozen, no music on the 3 ToS
-i close the server -> all clients got a "connection lost"
-i tried with only 2 ToS (1 ToS client/server[my computer] and 1 ToS client[my friend])
-my friend tried to load hi save game
-but it give the same result -> game frozen
any idea ? Is it a bug ?