I'm having a serious problem with the performance of my Tyros 5...

Let's say I have three Registrations set for a particular song (saved as a Registration Bank comprised of three Registrations), and that on each Registration, by way of example, I have a left hand instrument (say, Strings), and on the right hand, to keep it simple, one instrument (say, E Piano)...in some instances, the instruments will be the same on successive Registrations (say, Registrations 1 & 2), with the only difference between the Registrations being the octave setting of the left hand Strings, or maybe the vocal is set to harmony on one Registration and not on the other...(I mention this to make clear that the problem I'm having is not the "noise" that sometimes occurs if you go from a Registration that has, say, Strings on the left hand to one that has, say, Horns on the left hand)...

More and more often (today, almost every time I played a song), when I go from one Registration to another the left hand instrument (Strings, in the example) "freezes", ie, it keeps playing in the key it was in when I switched out of that Registration...as I try to play the new Registration settings, the last left-hand Strings note I was playing in the prior Registration setting persists...it even continues if I stop playing altogether...almost likes it's "shorted out" or something...despite trying nearly every button on the keyboard, the only way to get it to "un-freeze" and stop playing is to turn the Tyros off and then back on...

Has anyone else encountered this problem with their Tyros (or Yamaha board)? Is it possible a software update might repair the glitch?

Thanks,