Original VoiceLive is getting squirrely


I have the original VoiceLive local processor which I love but lately I've been having some problems. When trying to change from song mode to step mode or step mode to present mode The processor loses its mind for a little while showing mix in the read out. Usually it will calm down and go we are on direct after a while. Also when setting harmonies in preset moon the third voice control often will not respond properly. Is there a firmware update that might correct these prongs or should I send the unit in for a refurbishment? I don't have proof of purchase as I purchased this unit used several years ago. Will that be a problem? Thanks for your help