Yeah, that's the NOR gateway if I am not mistaken, looking at the weather maps it looks like there was possibly some bad weather in that region today around that time.  After a short while if the modem can't get connection to the gateway it will give up on transmitting data and wait for the recieve data to come back before it starts transmitting again.

It's also possible there was a gateway issue, or one really strange modem issue...  As far as software updates go, any time you reboot these modems in any way, they will go through a software update.

NOR = North Platte, NE