Which version of the XDK are you using? Do any of the examples compile properly?
You're unlikely to get much help with xtra development. There used to be a dedicated listserve when Macromedia owned Director, but it died and despite repeated efforts Adobe seem disinterested in resurrecting it or support xtra developers in any way. You might subscribe to Direct-L and ask there as there are a few (fewer and fewer) xtra developers who lurk there.