You need a newer revision of XBMC. Check the "usual places" or pay T3CH a visit and get a later build. Latest is T3CH XBMC 2007-04-20 SVN rev8582-MIDI.
Reading up, I guess you will need an even newer build since this skin uses very new elements of the XBMC skin engine. If you get some more errors from that build you will have to wait until T3CH builds a newer one, or maybe you can find a newer one in a not so usual place.
You can "pay T3CH a visit" here:
http://217.118.215.116/Am I allowed to do that?^I don't see why not since that link was posted on X-S Front page when the build was released. I didn't even know he had a mini-site until I clicked that link
Very sleek and has a low profile look to it. Matches my black themed entertainment center perfectly