[arch-general] Running setserial from rc.local

With the new Xorg, I need to run the command: setserial /dev/ttyS0 port 0x0200 irq 5 autoconfig At every boot to get the stylus working in a Tablet PC. I have put the line in /etc/rc.local, as it contains "all the things which are not daemons that you want to run at boot". But it is not working. KDM (therefore, X) starts without using the stylus. If I switch to a terminal, run the command, and the return to X, the stylus is recognised. Any clue about what is I am doing wrong? I know that the command can not be executed from an X terminal (this is why I switch to a "normal" terminal), but running it from rc.local should work, right?