Thanks, I checked the site and it says:

The power button turns on the tablet with a shortpress press as opposed to the longpress normally required.

N900: The keyboard backlight behind the left and right side of the keyboard flickers in response to system activity.

which is exactly my problem

so do I have to reflash my N900 again?

and where do I use: flasher-3.5 –-disable-rd-mode ... while flashing the emmc or rootfs?