I installed my button kit yesterday (4-LED knob board - way cool!) and am experiencing these problems.
1. It is very difficult to select the illumination level, because the button control PIC also controls the LED's, and there is a conflict condition. The fix would probably be for Hijack to wait until the knob is no longer being turned before sending an updated brightness command to the display board.
2. The illumination flickers when the knob is rotated or buttons pressed - fact of life (see 1).
3. The headlight sense completely confuses the illumination code - I usually lose the LED's after switching my headlights on, until I pull the player and reboot. The empeg headlight sense code works fine.
4. My LED's also stay lit after power down, until the shutdown timeout when everything switches off. I thought that might have been a feature.
Rob