jerky/slow animations in IE

jerky/slow animations in IE

:cry:
i've built a fairly simple website with modal window.
when it fadeIn, its very slow..only in IE (6 an 7).

you can experience it in here http://www.v-catalog.com/yair/hamismacia/

its in Herbew, BUT you can just click on a link near the numbering (big list).

why is it so damn slow?
i've written the exact same on my other websites and it runs fast even ion Ie6 :/