Rebellion Multiplayer Freeze and Lag

[JediMaster9780]

My friend and I are connecting to play Rebellion multiplayer over a direct serial connection. We are using Hamachi and HW virtual serial port to make the connection. While playing we do experience lag in the game. We have the speed set to medium. Sometimes the lag will go away and we will be able to play again. What usually happens is we reach day 75 or so, and the game will lag to a point of no return. We have tried playing the game with and without Rebed cards and we don't last much longer than 150 days. How can we fix our lag problems?