I removed the possibility of crosstalk with my cable modem by separating the coax running to my office from the rest of the coax in the house. This way, the MI424WR's sit on a single piece of coax and only talk to themselves. I have purchased 3 MI424WR's total as one of the original two I purchas3ed for this use died mysteriously after 6 months. It could have been more an environmental failure (office, small space, pet fur) than hardware, but I'm reconfiguring my desktop layout to account for this.
That said, I enjoy having the hardwire connection when my 30-foot, through-three-walls, oft-dropped WiFi connection annoyed me to hell and back.