adding fonts with fop-0.20.4

Hi,
has anyone had any success with adding fonts in fop-0.20.4 ?

Currently I'm getting an error message "Failed to read font metrics file
c:\Content\Fonts\arial.xml" which refers to my absolute path of the
userconfig.xml file (as below). If I run without userconfig, I get a warning
message indicating that arial was not found and is being substituted by
another font.

userconfig as below:

<font metrics-file="c:\Content\Fonts\arial.xml" kerning="yes"
embed-file="arial.ttf">
    <font-triplet name="arial" style="normal" weight="normal"/>
   <!-- <font-triplet name="arialMT" style="normal" weight="normal"/> -->
 </font>
 <font metrics-file="c:\Content\Fonts\arialbd.xml" kerning="yes"
embed-file="arialbd.ttf">
    <font-triplet name="arial" style="normal" weight="bold"/>
   <!-- <font-triplet name="arialMT" style="normal" weight="bold"/> -->
 </font> etc....

fop command line:

java  org.apache.fop.apps.Fop -c c:\fop\conf\userconfig.xml -xml
input.xml -xsl customisation_ fo.xsl  -pdf c:\Output\myfile.pdf

any ideas? cheers, Mark