Hi Tom Cavanaugh
1 - After read your problem, Yesterday night, I made the same procedure on my PSR 740, as you report, and my keyboard works properly.
2 - About voice set: At Functions Utility, if you put Voice set - OFF, a lot of configurations you like as: effects, harmony, volumes, R2 voice, and so on, will not change when you choose other voices.
But pay attention that Registration memory is the master in this matter: if you call a regist, all the configuration that are in it, will be called. After, these configurations will be the actual if you call another voice (if voice set is OFF).