xref with insert.xref.page.number returns ?

Hi,

I am working on eSvn [http://esvn.umputun.com/], an Open Source project to 
build a GUI interface to Subversion. Sources can be obtained from eSvn 
repository [svn://esvn.umputun.com/esvn/trunk]. Contributions welcome:-)

For FO, I notice that with "insert.xref.page.number" set to "1" the page 
number is sometimes displayed as a " page number " and at other times as " ? 
".

For example, in the following sample copied from an "itemized" list, the first 
"listitem" with a "xref" to "esvn-tree-view" shows [9] as the page reference. 
Yet the other two using the same "xref" values for "endterm" and "linkend" 
show as [?].

Why?

<listitem>
 <para>&view-refreshlocal;: Refreshes the <xref endterm="esvn-title-file-view" 
linkend="esvn-file-view"/> of the folder selected in the <xref 
endterm="esvn-title-tree-view" linkend="esvn-tree-view"/>.</para>
</listitem>
<listitem>
 <para>&view-refreshworkspace;: Refreshes both the <xref                     
endterm="esvn-title-file-view" linkend="esvn-file-view"/> and <xref                     
endterm="esvn-title-tree-view" linkend="esvn-tree-view"/>.</para>
</listitem>
<listitem>
 <para>&view-refreshonline;: Refreshes both the <xref                    
endterm="esvn-title-file-view" linkend="esvn-file-view"/> and <xref                     
endterm="esvn-title-tree-view" linkend="esvn-tree-view"/> and compares the                   
revision number of all local files with those in the repository.</para>
</listitem>

OS: SuSE 9.1
Toolchain: Saxon 6.5.3, fop-0.20.5.
Docbook XSL: 1.64.1-71

-- 
Sean Wheller