I'm having a similar problem, but it's more like a slight annoyance. The Volume up and down buttons are switched, so everytime I press down, the volume goes up, and vice versa. I tried to edit button configuration using Waterlily, but the option was greyed out and I didn't know how to activate it. This is a picture of my player (similar to the one taddad reviewed several months ago):
It has version 9.0.43 firmware. Anyone know how I could switch the configuration? Thanks