NetGear Residential Gateway CG3000D-RG

I continuously lose internet service at random times during the day/night. It seems tied to the cable modem/gateway rebooting - but I don't actually look for the lights on the modem to see if they have changed status or not. I know something has happened because the network status icon in the lower right corner changes to a yellow ! triangle sign. After a few minutes it will go away and I can use the internet again. However I have noticed that there is this message that appears every single time I lose internet connection in the event log:

Now the "Notice (6)" means that this is the sixth time since Sun Apr 21 00:00:01 that this TLV-11 has appeared. It also means that the modem has lost signal/rebooted six times. I don't know what the message means, but I do know there is a direct correlation between this messages appearance and me losing internet connection. 

Here is my current signal levels - something no tech has checked at the modem/router side. I cannot correlate what the signal levels are at the time or just before the TLV message because this modem/gateway is not sophisticated enough to record both apparently. 

I also don't know if there is anyway to update the firmware on this, outside of replacing the modem. But it does appear to be some sort of "reboot" that is occurring, note the system up-time is set to less than an hour

I don't have faith that Cox can fix this issue. I have had three (four this afternoon) techs out to look at this problem. I get the same answers, well the signal levels look fine. Really? Is that the extent of your troubleshooting skills? I have a nice apartment in a decent location with a garage. I'm willing to give up the garage and the location to move somewhere else in order to get FIOS.