Parties Being Split Up

I'm sure this has been reported already, but sometimes, when forming in-game parties (outside of X-Box Live Party chat), the groups of players are split up between teams when joining games already in progress.

Is there a way to prevent formed teams from being split up and/or joining games already in progress?

Not only are you often split up when joining in progress games, you'll occasionally be split up when starting a totally new game for reasons that aren't readily apparent. Maybe it's because there are other parties and there's no way to keep all the parties together and keep even teams, but I don't know.

I don't really mind being split up for in-session games too much. Usually those are over fairly quick.

I'd rather be split up temporarily than have to wait further to join a game. I can't see a way to manage to balance out an in-progress game and keep parties together without swapping teams around mid-game, and that would suck.

As faits mentions, it also happens in existing lobbies. That's more annoying, but the question is, can it be helped?

yeaaa i had tht we majority of the time just leave the game and party back up again