SVG defs use relation between different figures Fire Fox

"[email protected] [svg-developers]" <[email protected]> 30 Jul 2014 14:25:36 -0700
Newsgroups gmane.text.xml.svg.devel
Message-ID <[email protected]>
We've got a simply code, which works cross-browser:
 <html> <?xml version="1.0" encoding="UTF-8" standalone="no"?> <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="200" height="100"> <circle id="circ" cx="120" cy="40" r="30" fill="green"/> <rect id="rect" x="10" y="10" width="60" height="60" fill="blue"> <set attributeName="fill-opacity" to="0.5" begin="circ.mouseover" end="circ.mouseout"/> </rect> </svg> 
 When I try to use the elements in defs block I'm losing relation between two rectangles in Fire Fox browser.
 <html> <?xml version="1.0" encoding="UTF-8" standalone="no"?> <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="200" height="100"> <defs> <circle id="circ" cx="120" cy="40" r="30" fill="green"/> <rect id="rect" x="10" y="10" width="60" height="60" fill="blue"> <set attributeName="fill-opacity" to="0.5" begin="circ.mouseover" end="circ.mouseout"/> </rect> </defs> <use id="use_circ.rectangles" xlink:href="#circ" /> <use id="use_rect.rectangles" xlink:href="#rect" /> </svg> 
 I've read something about relation here http://www.petercollingridge.co.uk/data-visualisation/mouseover-effects-svgs http://www.petercollingridge.co.uk/data-visualisation/mouseover-effects-svgs? , actually this words "Note that this effect does not work in Firefox Firefox 6 and earlier (I think), which is perhaps the biggest drawback of this method. "
 
 I need to press the button to move(change) another element. I also tried to make something like this, to set relation effect: