To install udev rules, run `make unix-install'. It works on Debian
(squeeze).
It seems that permissions are not set properly if the devices are
already plugged in before boot (maybe because they are here before
udev is started?). To solve this, you can put the following line in
your /etc/rc.local:
lsusb | awk -F'[ :]+' '/ID 04d8:/{print "/dev/bus/usb/"$2"/"$4}' | xargs chmod 666