I had a similar issue when I upgraded my AVR to a Maratnz NR1603.
My original solution was to use optical to the AVR and HDMI straight to the TV, after exhausting every other suggestion. (tinkering with driver settings, reinstalling PlayReady, disabling pretty much everything on the AVR)
One afternoon I got bored and started tinkering, and it turned out (for reasons still unclear to me) that it was a problem with a particular HDMI input on the AVR. After I switched to a different input, everything worked fine.
I'd say it's worth a try.
RAID protection is only for failed drives. That's it. It's no replacement for a proper backup.