Be seems to be doing very well at the moment -
id recommend Netlimiter for network shaping (just schedule the 2nd computer to slow down during certain times - so yo ucan play, 2nd machine gets say 8-10 k down and 5 up - more than enough for browsing / plain chat windows...
you could keep resyncing but why would you want to Leave cable ? id >prefer< cable - as im in the habit of working around PlusNets usage policy (20gb cap peak - uncap offpeak) you get the most of your line.. i cant get more than 1mb - or you could just unplug the 2nd machine and say the internets down..