I just told the Harmony software to map the device as an Apple TV. When you go into XBMC on the ATV1 you dont need to do anything it just works. You get the Fastforward, rewind, stop, play/pause, skip chapter, back chapter all work on the controller.
Similarly on the ATV2 you do not need to do anything. Until tonight none of the buttons mentioned above have worked but since installing the latest build 27th? most of the buttons now work again
The only buttons that worked were the arrows, ok and back.
However the pause and fast forward buttons do not work evn thou I have not installled the BTStack as suggested by dazex.
Hopefully we will get the Fastforward sorted soon. The pause isnt a big deal as the play button acts as a play/pause button anyway.