I read at least 2 other posts on the forums where this happened to someone. My friends and I will be playing a locally hosted game, 3v3, and the game will lose sync among players. We don't notice anything out of the ordinary until we start calling out a play by play on a planet and the other person has no idea what you're talking about becuase there are no enemies on their screen at that planet.
Manually saving the game and loading the save game does NOT fix the issue. Reverting to an auto-save, sometimes it takes multiple itterations to find a good one, will work.
Any ideas? Solutions? No dumps are generated and the game will just keep on playing.