Connection keeps dropping with SB6121 modem

Over the past two weeks, I've had daily issues with Internet connection dropping.  I've had the SB6121 modem for over a year now, and this is the first time these issues have occurred.  

I've contacted Xfinity support three times now.  Two times, they were unable to locate my modem in the system and I had to provide all serialized information to them.  I've found that I can completely unplug everything, reconnect and the connection is restored.  My suspicions are that there is an issue with the firmware.  

Does anyone know of an update?

My information, error logs, and configuration are:

Model Name: SB6121
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.10-SCM00-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.18m3
Hardware Version: 5.0

TimePriorityCodeMessage Jul 12 2014 06:15:31 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=7c:bf:b1:d3:bc:9c;CMTS-MAC=00:01:5c:25:48:30;CM-QOS=1.1;CM-VER=3.0; Jul 12 2014 06:15:30 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=7c:bf:b1:d3:bc:9c;CMTS-MAC=00:01:5c:25:48:30;CM-QOS=1.1;CM-VER=3.0;