SVG - links?

Hi
 
I am relatively new to SVG - I have done some basic things
to try it out, but need to understand some of the power in its
ability to create 'reusable' graphics.  However, I am unable to
get the xlink in the simple exampe below to work (rather, it does
not display properly when loaded into my IE browser, using the 
Adobe plugin as neither the second or third xlink display the 
rectangles with the width and height specified, although they are
at the correct y-position) - any help  would be  appreciated!
 
Derek
 
Code:
 
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20010904//EN"
"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg width="8cm" height="6cm"
xmlns="http://www.w3.org/2000/svg">
 <desc>Local URI references within ancestor's 'defs' element.</desc>
 <defs>
  <linearGradient id="Gradient01">
   <stop offset="20%" stop-color="#39F" />
   <stop offset="90%" stop-color="#F3F" />
  </linearGradient>
  <rect id="shade1" x="1cm" y="1cm" width="6cm" height="1cm"
fill="url(#Gradient01)" />
  <rect id="shade2" x="1cm" y="1cm" width="6cm" height="1cm"
fill="url(#Gradient01)" />
  <rect id="shade3" x="1cm" y="1cm" width="6cm" height="1cm"
fill="url(#Gradient01)" />
 </defs>
 <!-- test xlink -->
 <use xlink:href="#shade1"/>
 <use xlink:href="#shade2" y="1.1cm" width="2cm"  />
 <use xlink:href="#shade3" y="2.2cm" height="4cm"  />
 <!-- Show outline of canvas using 'rect' element -->
 <rect x=".01cm" y=".01cm" width="7.98cm" height="5.98cm"
   fill="none" stroke="blue" stroke-width=".02cm" />
</svg>

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