Watch the static. I played the UltraNova at a jam last night and was setup on carpet. I touched an encoder got a static discharge and the touch sensing stopped working. I just did a quick reset by turning off, unplugging, replugging, and turning on and the UltraNova came right back up.
I rubbed dryer sheet with fabric softener on the carpet and problem was solved for the rest of the night. You can also mix water with a little fabric softener into a squirt bottle and spary it on the carpet.