Thanks, Dave224 and plazman!
I'll try the 1080i setting. I had had that set earlier but mostly used 720P.Update: tried 1080i, still had load problem.
I agree problems like this could be HDMI handshake related. Last night I think I ruled that out, going through several dozen iterations of powering down just the HD-A20, letting it sit, sometimes unplugging its power source completely and letting it sit, repowering it - sometimes with the media already in the tray and sometimes not - trying to find the magic set of keystrokes to get the HD-DVD disk to reliably play.
All through these tests I kept all other components powered and available - TV, AV receiver, etc. Also tried lots of disk swapping - having read in these forums and elsewhere that that could be a factor.
This took literally hours - I was quite persistent. Bottom line: no sweet spot. No combo of behavior that I hit on, would make the disk reliably play. (Heartbreaker!)
So that's how I've concluded it's time to reject this unit for - whatever - having put it through its paces first.Update: Amazon makes defect exchange easy, plus I can test the replacement alongside the originally shipped unit, as long as I return the defective unit within 30 days. So it's settled. Thanks for responses. Will let you know how it turns out. - JerryFinal Update - SUCCESS!! I'm pretty thrilled!
See my full report on the previous page. Many thanks to all who helped.