Hi, sorry for the noise..
We need a clueful Comcast person to start checking out problems in their Atlanta headends. Over on the ALE (Atlanta Linux Enthusiasts) list there are a lot of highly educated engineers all seeing the same ongoing packet loss problems at multiple points. Calls to Comcast result in us hearing that there is no knowledge of a problem and that they are more than happy to roll a truck ($$) to our doors to "diagnosis". Comcast, please save yourself some money and send the right guys to the headend(s) to troubleshoot using the data in these threads: