indexterm with zone attribute

[Richard Hamilton <rlhamilton@frii.com>]

I've been indexing a document and am having some trouble with the zone
attribute on indexterm.

When the zone attribute points to an id on a block that extends over
more than one page, I would expect to see a range in the output, but I
only see the first page.  Is that the expected output or is there a
problem somewhere?

Here is a sample:

<section xml:id="someid"><title>some title</title>
... section contents long enough to extend over
    more than one page...
</section>

If I use this indexterm (placed inside the section, though I'm not sure
that's relevant):

<indexterm zone="someid"><primary>topic</primary></indexterm>

and this section extends from page 4 to 6, I would expect the index
entry to look like this:

topic, 4-6

However, instead of the range 4-6, I'm just getting the start of the
range, like this: topic, 4

Does anyone know if I should be getting a range, and if so, is there
some parameter or other magic that I need to use to get a range?  I'm
familiar with the other style of getting ranges in indexes, but since
I've already got ids on the appropriate sections, I'd rather use this
method if I can get it to work.

I'm using DB 5.0, stylesheets 1.74.0, Saxon 6.5.3, fop 0.94, and the
basic index algorithm (though the same thing happens with the Kosek
index algorithm).

Thanks,
Dick Hamilton
http://rlhamilton.net