Band Width Monster

I just spent the day with the service tech from UVerse and found out that my Mac Mini seams to be knocking my bandwith way down when it is connected via Wifi or eithernet cable.

I am normally in the 22mbps, connect the Mini and boom, all my devices are knocked down to 1.2mbps, unplug it and I am istantly back to normal. (remember it happens on Wifi too).

Any insight?