Restart the SuperHub and see if it improves things, the fact it is not affecting average suggests it may be the hub not giving a high priority to ping responses
The green hump suggests you are doing something with the line perhaps, or that local congestion has got very bad.
The shared nature of the local segments on cable networks means the behaviour of others in your area as well as your own use has a greater bearing on latency, than for the various xDSL networks.
There was some packet loss last night but I'm not seeing the 'hump' I had seen previously around 10pm. I was getting that each night around the same time! I wasn't using the network at the time.
I will continue to monitor but I guess it is to do with capacity in the area.