Graham. Good to hear that it's not just an anomoly (bug?) with my keyboard (Tyros) alone.

Thankfully, for most of my playing scenerios, I prefer to keep the left voice always set to 'acoustic' piano, and using my workaround method: http://www.synthzone.com/ubbs/Forum37/HTML/010030.html able to achieve this, but there are OTHER times when I do want to utilize the Preset style's OTS 'left voice' selection as well, and this is not possible with the LEFT voice continually shutting off when merely switching between OTS buttons 1-4. This makes absolutely NO SENSE to me whatsover. Is this a major "OTS Preset Style" design flaw on Yamaha's part?

Scott