Hybrid and his brother share the same DS, so half that. They are both very good though.
I've notice people dropping before the game starts, the lights just disappear, and it's sometimes with 2 or 3 people there, so I doubt it's a coincidence that they all just left. Maybe it means they joined a different game? It's not a huge issue for me though since whenever that happens other people just come on straight away.
By the way, what other countries actually have the game? It's only officially out in the US and Australia, so I guess i'm always playing Americans in that mode.