Not without seeing the diagnostics you were given !!
My _guess_ would be that the "xyz.xml" file includes some
sort of relative URL in it (e.g. for the DTD). To fix that
class of problem, just feed argv[0] directly into the
document builder so that the parser can resolve it, or else
modify the document so it doesn't use a relative URL. This
particular issue is noted in the method's documentation,
but it nonetheless seems to get a bit of confusion.
- Dave