(REVISED AND SNIPPED POST 26/04/2016)
MZ-X500 reported issues, awaiting fix.
From Synthzone.com topic Casio MZX-500 Issues., Please Read!, 25/04/2016
(major surgery snipping of post) 26/04/2016)
cheers for reading, am confident Casio can fix this. Just pre-ordered my own MZ-X500 and looking forward to it.