I assume you are talking about jrgutknecht's problem:
The only issue I've encountered is a "stuttering" of the live picture from any of the 1-100 channels over HDMI. It's not there when viewing over component, only over HDMI. Could this be why they want me to change??
I haven't heard anybody running into the problem. I have TW instead of Comcast, and my box is a Pace DC-550. It sounds like the 1070's DVI switching will be coming in handy for you.