What's going on here?

Assume that url = "http://www.foo.com/bar/xyz.xml" and that I can see
xyz.xml (and its in my local domain) from Internet Explorer on a PC. Now I
go to my Mac and run some code like this:

     anchor = HTAnchor_findAddress(url);
     request = HTRequest_new();
     chunk = HTLoadAnchorToChunk(anchor, request);

Chunk comes back with a zero buffer address and a zero buffer length. ARGH!
Any ideas why this might happen or how I can debug what's going on?

regards,
-jim