not so super superscript

Actually, the subscript isn't too great either. I'm finding that the
superscript is nearly the same size as a regular character and that it
not raised above regular characters. It looks particularly bad when I
use superscript for references. Similarly, the subscript is not really
sub at all.

For example, these letters all turn out the same size:

<emphasis>w<subscript>ph</subscript></emphasis>

A second problem is that in order to keep the super/subscript next to
a letter, it has to be included within the <emphasis>, otherwise a
space is inserted between the two. For example:

<emphasis>R</emphasis><subscript>o</subscript> 
puts a space between R and o. For time being, I've moved the emphasis,
but now my subscript is forced to emphasize, too.


I'm using Oxygen (OSX) saxon/FOP to generate a PS file with

<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
                      "file:/Applications/oxygen/docbook/dtd/docbookx.dtd">

and this stylesheet

/docbook/xsl/fo/docbook.xsl

Thanks for any advice you might have on making my superscript super.

Casey