I hawe a problem on the SD90 with that 2.10 software. It happened to me when I inserted a multisample and went to edit it, it would mute itself, and mute the whole keyboard. There would be no rhythm or sound. The only solution was to turn the SD90 off and on again.
I downgraded the operating system to 2.07 and now everything is fine, everything works, and I don't have any such problems. I even feel that sounds and rhythms sound better. Maybe I'm wrong, but I solved my problem with 2.07 os