IE7 .show() - .hide() problems

IE7 .show() - .hide() problems

Hi,

I'm working on a website with some simple jquery effect to show and hide multiple div at the same time.
Clicking on a thumbnail with specific title attribute, I want to show corresponding div.
The page works fine in IE8 (animations are not so fluid), firefox 3.6, chrome 5.x.

You can view the page here: http://emilione.altervista.org/works.html

How to reproduce the problem:
-click on (x) thumb: content div appear
-click on (x) thumb: content disappear
-click on (y) thumb: (y), (x) and often other content appear together

Looking at IE8 Developer Tools (IE7 Browser Mode), css "display" property seems to be set correctly, but the result is not good.

I hope for your help!
Thanks

(Sorry for my poor english)