If I change channels with my HR23 after I have a picture, it takes from 5 to 10 seconds for the channel to switch. Slightly slower than my HR24, but that might be expected. If I use the PREV switch, the channel changes in 3 to 5 seconds. This phenomenon, No Picture After On (NPAO) only happens after the HR23 has been off for a while, like several hours, usually more than two. ON and OFF and ON again every so often always produces a picture. If I turn the HR23 on and get NPAO, and press the RECORD button, nothing happens. If I get NPAO and I quickly PLAY a recorded video from the LIST, I get a picture immediately. Also, to reiterate, if when I have a NPAO and I press PLAY, the time and program status bar oftentimes displays a time and a program that have been over or several hours (more than 1 1/2 hours). I still don't know what to make of that. On the HDMI handshake, I've got some experimenting to do. The HR23 is on HDMI 3. When the HR23 is OFF and I switch to HDMI 3, usually there is a graphic on my screen from the TV that says "NO DATA." Sometimes however, that graphic does not appear. Maybe that means there is no attempt at handshaking at that time? I'll have to check and see if that graphic finally appears after waiting a while before I turn the HR23 on. Also I'll have to see if I get NPAO or an immediate picture depending on whether or not that graphic is on or off. Thanks!