It's the best fix for IE not supporing the CSS property "position:fixed;"...
I done an alternative CSS+Dynamic Properties (IE only) solution to make IE do position fixed, and no extra code needed on the element itself!
it's all in the CSS, but scripts probably still have to be enabled in the browser.
IE5+ I think.
check it out the IE version of position:fixed; here!
http://dev.jdenny.co.uk/css/ie_fixed.html
*edit* updated to include a fix for background-position: fixed;