I agree that is happening with some ISP'S, but not all. Friends have Comcast as an ISP, and after installing a VPN, the problem seemed to be much better. It looks like it is happening to more ISP'S than we thought.
I am not sure about it being a Rocket problem, the forum would be flooded with people complaining about this. There are some complaints about VOD issues. But anyway, good luck, hope you figure this out.