All you need to do is recomplile the kernel to get the following modules
download http://gatos.sourceforge.net/ati_remote.php and put it in /usr/src and make sure there is a linux softlink to the correct kernel (e.g. ln -s /usr/src/linux-2.4.21 /usr/src/linux)
compile the ati_remote.o module and put it with the others in the /lib/modules dirrectory of the minimyth root.
then edit the /etc/lirc.script to include and ati section
mount -t usbdevfs none /proc/bus/usb
(the mount needs to be done before loading the ati_remote module)
and the arrow keys and ok button should work straight away. The ati remote is different to other lirc remotes and it is seen buy the kernel as a keyboard (and mouse ). To configure the keys you can either edit the source code, need to can one to be an ESC key, being careful wih the abcdef buttons alone as these can effect any normal keyboard attached. The other method is to use Xmodmap which I haven't tried yet, and at a guess isn't avaliable under the current minimyth X.