Page citation formating problem in PDF

Hi,

When I turn on page citations for xrefs, I get a strange formatting 
problem on the generated text:

About 5 blank spaces follow the page number (the blank space is 
clickable and links to cross reference). Also, the closing bracket 
immediately follows the first number, overlaying the second digit in any 
2 or 3-digit page reference.

Furthermore, this problem occurs on most xrefs, but for no apparant 
reason, not all xrefs.

The attachment shows the formatting problem.

Has anyone seen this before?

I'm using
fop 1.92beta
docbook xsl 1.70.1
Saxon 6.5.5