crosslinking between pdf documents

Hi all,
  I've got a collection of docs to be outputted in pdf (and html) and
the docs contain links to other docs in the collection.
I've got olink working with the html. It links correctly with chunk
and no-chunk.

I'm can't get the links to work between pdf docs though.    It opens
the first page of the targetdoc, not the section the link points to.

I'm using xsltproc (xmlto) and read that  xsltproc removes the fragment ids.

I've tried insert.olink.pdf.frag=1 but that doesn't work either;
acroread tries to open a bad address inside the web browser.

Any ideas?
thanks.
matt