insert.xref.page.number ignored when using xreflabel

Using the 1.72.0 FO stylesheets, I noticed that xref has a page number
reference appended when a xreflabel is used, even when
insert.xref.page.number is set to "no" (the default).

For example, if I slightly tweak one of the cross reference examples
from Bob Stayton's book to include an xreflabel:

<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<book>
    <chapter id="intro">
        <title>Introduction</title>
        <para id="c1p1" xreflabel="Paragraph One">
            Welcome to our new product. One of its
            new features is a <link  linkend="WidgetIntro">widget</link>.
            Other new features include ...
        </para>
    </chapter>
    <chapter id="WidgetIntro">
        <title>Introducing the Widget</title>
        <para>
            Widgets are just one of our new features.
            For a complete list of new features, see <xref linkend="c1p1"/>.
        </para>
    </chapter>
</book>

I get the following output for the second paragraph:

Widgets are just one of our new features. For a complete list of new
features, see Paragraph One [1].

The [1] reference isn't there if xreflabel isn't used.

I'd like xref to have the same behavior in all cases; any ideas on how
to turn of the page number references in the case where xreflabel is
used?

Thanks,
Ken