I discovered, after writing my post, that the problem wasn't Netflix or Roku. It turns out that episode 9 of this HD series is not in HD. I realized this when Ep 10 downloaded in HD as had all the others. The "cover" on the instant queue screen indicates it is HD. The information screen on each episode is HD, except of course for 9. It could be a Netflix problem, but it has minimal impact...so in the words of Emily Litella, "Nevermind!"