It's certainly a strange one Roger, for example I re-installed the same version firmware earlier this evening, and though I admit I was a little sceptical when Joe said it seemed to improve things on his 970. However having done the same thing, so in effect I'm still running the same version firmware but re-installed, and further testing while setting up more registration banks does definitely show a big improvement, which sort of defeats all logic...lol. It hasn't cured it 100% as it exited twice earlier, but it's certainly happening much less, indeed if it stayed like this I'd be perfectly happy. Just twice in one evening is a **** of an improvement compared to how often it did it previously.
That's the main problem Roger, it's not like something you can put your finger on, we are all trying different things just to see if it alleviates the issue, as Joe has been doing to his credit. In reality re-installing the firmware shouldn't make a scrap of difference, but it has definitely improved things, so now we have to ask why ?
As far as I can see it's not changed any of my settings by re-installing it. I just set up a extra 3 registration banks so thats 30 in total which in the process I went through quite a lot of various voice mixes with the odd change of octave to one voice to get the sound I liked, so a lot of button pushing and it never gave a problem, though I do think my getting in the habit of pressing near the outside of the button every-time is playing a positive roll too, IOW I've learned how to press them to avoid the issue, and so I tend to do it automatically now.
I do think, the problem is caused by it picking up a double press of the button, so likely a hardware issue of some sort, but at the same time I suspect a small time delay of a few milli-seconds after detecting the first contact would possibly solve it too.
The problem is if your a manufacturer who say has sold say 50,000, and you have few dozen with this issue but no-one else is reporting it, you are unlikely to issue a potential firmware fix that may or may not fix it, and risk issues with all the other 49,800+ boards out there which to all intents and purposes are working fine. Therefore the only option for Yamaha is to advise those afflicted by the issue to send them in for repair, and I suspect because it's not a major issue, not many will bother doing so, myself included, unless it begins to get worse of course, and I think they know that, as probably very few have been sent in for repair.
The big question is why should a re-install of the same version firmware noticeably improve things, surely that is telling us something ? clearing out some crap..lol some setting being reset...weird..Joe always reckoned that a system reset helped his 970, coincidence or not, it's so hard to tie it down...we need a Sherlock Holmes on the case.
I wouldn't mind so much if Yamaha acknowledged the issue, and came up with a few idea's, but they won't do that as it would be admitting there's an issue with some models, and Yamaha Keyboards are perfect...right!....well their piano could be better...lol sorry couldn't resist that..lol