I have power button working on the n810 using events from /dev/input/event1 and long presses are ignored by ASUI allowing MCE to shutdown with them. Only problem is that mcow says it doesn't work on n800 so I need someone with an n800 to figure this out. Are there a bunch of numbered event files in /dev/input? If you run cat /dev/input/event1 and press/release power button it should spew garbage to console, repeat this by changing the 1 to different values until one of them works.