But let's try this. Is it on WiFi? If so you are eating away at a very limited resource. Any chance of putting them on their own WiFi? An old trick of mine was to set their WiFi to 802.11b which will limit the speed a little and you can get your own WiFi.
Just looking for how I can solve this problem: my 2 sons play Xbox Live on Xbox, and try to claim that when it isn't connected to the Internet it doesn't hurt the connection at all. I know it does, though, and was just looking for some verification and help how to fix the problem. Also, if the Xbox is connected to the Internet, how much does it hamper the connection for, say, my laptop?
Thanks in advance!