[jQuery] slidetoggle jumps in IE

I am having an issue with the way a slidetoggle animation works in
IE. I am using the animation to show/hide div's here:
http://stonebergdesign.com/clients/coop_test/wordpress/about/
in FF and Safari the animation works great. In IE the div briefly
display before and after it shows/hides. I am not a whiz at jquery
and most of the code was copied and pasted... Any help is greatly
appreciated.