Dont use the same service, but do have charter and use the same motorola modem. When this happens I usually get several messages something like this in the log:
MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
ToD request sent - No Response received;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
1) GOTO the modem setup page: »192.168.100.1
2) Click on "Configuration"
3) Click on "Reset All Defaults"
4) You will get a prompt that makes you worry...Don't, it will be okay. Answer yes.
5) Go to your modem and unplug the power from it and leave it unplugged for at least five minutes.
[5 minutes have gone by]
6) Plug your modem back in.
7) It will take your modem several minutes to relearn the route paths and download the config file from your ISP.
8) If this works for you, write a confirmation post here so that others might benefit from it.
I hope this helps.