Banhammer for connection-only in a fireteam. Help!

So I have just been banned for the second time due to my ‘connection to the dedicated servers’.

If I play on my own, I very rarely d/c from a game, and it has never resulted in a ban. My internet connection isn’t the best by a long way, but 9meg with a low ping seems to work just fine when I am playing solo.

However, now on 2 occasions when I have been in a fireteam with a buddy, I get d/c right at the start of a game. This happened 2 games in a row and I have just been banned for 3hours 45 mins (the first time it was <1 hour).

Does anyone else get more issues when partied up? Any idea if there is a way of reducing/removing the ban? My connection when playing solo is fine and its not like I am trying to play when I have torrents d/l or anything else active on my network.