How come on Xbox live games, my friends that are on (Virgin) cannot host as everyones connection goes v poor?

Only happens to people on virgin, the game has to end its that bad.How come on Xbox live games, my friends that are on (Virgin) cannot host as everyones connection goes v poor?
I'm on Virgin and my connection can usually sustain a game, get them to ring up and ask if they're over paying, I was meant to be on triple the speed I was paying for.How come on Xbox live games, my friends that are on (Virgin) cannot host as everyones connection goes v poor?
It seems that the connection at their end is poor, you can only play as fast as the person with the slowest connection. They will have to check that anything at their end isnt ripping the a*se out of the connection, like on their network at home a computer running utorrent (especially utorrent), or someone wathing iplayer in HD, or something like that. Then if they checked that thye should give virgin a ring if nothing is sorted.