I am a novice player and use the autoharmony feature to add harmony notes to the right-hand melody. I purchased a PSR540 and unlike all previous Yamaha PSRs, the harmony function is almost unusable because it requires that the left hand chord be playing before the melody note is depressed. All previous PSRs have exhibited "don't care" about whether chord or melody was first depressed. I have checked other PSR540s and they are all the same. I feel this is a design flaw. Any comments ??