A post on the forum talks about duplicate modem MAC address as a possible cause. I believe that this could be it. I do recal seeing one of those quick warning poping up about duplicate mac address. Did not pay much attention to it at the time but tought that it was strange. A friend saw the samething on his pc. Unfortunately I have yet to find the right person at Rogers to investigate this issue. A simple test would be for a tech at Rogers to try to log on to my modem after it has been disconnected. If log on was to be successful then that modem would definetely be a duplicate mac address modem.
If you have a SamKnows white box it is more than likely the culprit. It was in my case. I disconnected the box and everything came back to normal. Neither Rogers nor SamKnows make you aware of this although they will claim that any overusage will not be billed to you.