I have Shuttle Zen (st62k) that I have been using as a diskless Media Director. The ATI drivers do not support DRI on the Radeon 9100 IGP that is on this motherboard. In 18.104.22.168x I would set it as a standard video card, upgrade to Xorg and configure /etc/X/xorg.conf to use the "ati" driver. It worked very well.
22.214.171.124 comes with Xorg so I would suggest you do the same. In fact ATI support is so good in the open source xorg ATI driver, (unlike XFree86), that I would question bothering with the commercial ones.
Now the bad news. I have not made it work yet. In 126.96.36.199 I can not convince it I do not have an "Radion 8500 or newer", (at least it is correct), and so Pluto continualy overwrites my xorg.conf. Seting the MD to use vesa or removing the device in Advanced->Configuration->Devices never seems to stick. I can only assume Plug-And-Play is getting in the way.
Will let you know when I have a solution