Noticed a weird behavior with my PX but I'm not sure the best way to let the Sequential team know about it (via support ticket or something else). This is on the latest 2.2 firmware. Perhaps someone else would be interested to try it out?
If you want to try it, make sure your monitors are turned down: Just hit 'Revert All' while touching one of the sliders, and you'll get a loud, glitched out note repeat that only stops when powering down.
EDIT: Do NOT try this with headphones, somehow completely bypasses the volume control and it can be very loud.