[Speed Problem] modem or line? would this be an issue with the modem (speedstream 4100) or the line inside the building..... download speed's tested half of what they should be until the modem was restarted, then the speeds were reasonable. att states that they replaced the line to the nid but issue still continued. now received a letter from att that because the speeds are on average lower than the speed tier being paid for, they will "conveniently" lower the tier package automatically. so two things, 1) is it more likely the modem or inside line at fault and 2) any way to not have att "conveniently" change the tier package?