Unable to Connect - Why?!

I'm still curious about the matchmaking lobby system in GTAIV. While I've praised the game heavily since its launch, I can't help but notice how bloody difficult it can be sometimes to play against or with other players. Especially in a party, when we leave the free-roam lobby and decide to play Team Deathmatch (or whatever mode) it drops one of us, or disconnects the host and we all drop; or the lobby is so lagged that no one appears and we all quit to restart again. I understand 'growing pains' to a point, but when we're paying for Xbox Live this kind of situation shouldn't exist. I hope this gets patched soon.