Thanks. What I did do was move the shell that didn't fire into the left barrel and it fired there. However, I then used Federal's in the right barrel and had zero problems. Been using Federals all year with no problems, so I guess my assumption now is that perhaps there is a lighter strike on the right barrel then the left barrel and that lighter strike will still work with Federal ammo, but not the RIO's. Accordingly, I'm guessing that RIO primers are harder then Federal primers.
FWIW, I don't normally shoot RIO shells. I just happened to have box in the garage that I grabbed when I left the house yesterday.
