upgrade to diablo
download rootsh
type root in xterm

step by step from the wiki

the first thing u type in xterm is
(for the n810)
#1
apt-get install advanced-backlight osso-software-version-rx44-unlocked

#2
maemo-mini-curl -o kernel-diablo-flasher_2.6.21-200842maemo1rotationfast_all.deb http://outpo.st/rotate/kernel-diablo...onfast_all.deb

#3
maemo-mini-curl -o xserver-xomap_1.3.99.0~git20070321-0osso20083801rotation_armel.deb http://outpo.st/rotate/xserver-xomap...tion_armel.deb

#4
dpkg -i kernel-diablo-flasher_2.6.21-200842maemo1rotationfast_all.deb xserver-xomap_1.3.99.0~git20070321-0osso20083801rotation_armel.deb


then reboot