Multiplayer using Hamachi and suddenly friend defeated

[JKPG]

Hi all,

My friend and i are trying to play against eachother using Hamachi, but for some reason he just randomly loses. What happens is that after a couple of minutes or even after half an hour, it just pops up saying that he was defeated although nothing else has happened.. Can anyone relate to this, help us fix it or something? I guess he loses connection of some reason, but comeon.. how difficult can it be to make a game that actually works?