As I don't know which dev diary entry is the most active at this moment, I'm gonna copy paste my entry from the other dev diary here too and hope someone will see it. Apparently this out of sync bug is still quite a big deal and it really spoils the fun.
Me and my friend just played our first online game yesterday, we 2 vs 2 comps on Doppelgangers. He has the german version and I have the english one, maybe that could be causing problems?
Anyways, some time in the game we desynced. I was curious when I told him to attack some forces in my solar system and he asked where they are.
I then saw that they were actually attack his system, a whole fleet at his sun. I told him and he told me he does only see one scout there.
I was really like wtf but we got on, as we didn't know this bug yet.
Later he told me to come help as he was attacked by the other comp. I came and couldn't find any enemies. I then razed a colony of the enemy in his system (a dead asteroid my friend ignored) as he said that I'm currently fighting the enemy fleet and my shields were down. I looked at the peacefull picture in front of me and my full shields...
This was when we realized something happened. I looked for similar things alot and finally found this and the other diary entry about it.
Still, we have sync errors in the latest versions. We could aid in killing this bug, if we can reproduce it. And I bet we can as we are those friends that always seem to have problems playing together online... (mysterious things)