Punter, yes, I observe the problem with multiple components. I've tried varying emitter strengths. I've also tried IR only, and IR seems to work fine. After this, I plan to edit my original post to indicate that.
You said you had problems with converting from the MX-980 to the MX-990. How did you get around that? Did you create a new file?
Joe, yes, I did set the RF ID and transfer the change to the remote. It does work 25%-50% of the time, so I feel confident I've done that correctly. I'm familiar with that process.
Thank you, Joe and Punter!