My keyboard lock switch developed a fault which caused the screen to randomly turn on and off, sometimes in quick succession, making the phone almost unusable. This disables the lock switch until the next reboot:

Open a terminal
Gain root access (sudo/su/whatever)
echo 1 > /sys/devices/platform/gpio-switch/kb_lock/disable

I'd be interested to know of a way to do this every time the phone boots up. Tried a script in /etc/init.d and ran update-rc.d to activate it in rc2.d but no joy...