Sorry I have an H20. I can't even get my stats correct. And yes it appears I have an R15. You know this may be good time for me to finally upgrade to another HD DVR.Your H10-100 (Tivo model I believe) would be a problem unless you actually meant the H20-100. Since you've had your DVR plus since 2006 it is probably a R15 which means it isn't compatible. What you would need is the SWM8 multiswitch which has 3 legacy ports for non SWM compatible equipment.
Of course now I need to do something with my H20 (which I don't know if I can legally sell, and comes with a broken HDMI port), and my soon to be outdated R15....