After many (many many) times playing the new Crystal Crusade, I believe problems occur in multiplayer when one person has a slower PC and/or internet speed.

I believe the reason you guys in the office have no problems when testing, is because you all have fast PCs on a fast internet connection.

If the slowest person activates everything while others wait, then there are no problems. - but if a faster person activates something, while a slower person is still 'waiting' (for an animation to finish), that's when the players get out of sync and freeze up.

The separation of chat in multiplayer is very annoying... It's possible to miss what someone said if you look away from the screen for a second, because the multiplayer chat doesn't go in the chat log.