CSS, Internet Explorer 7: layout messed up when I click on a menu

In Internet Explorer 7, when I click on the menu in 'Categories' 开发者_运维知识库block, my website content slides to left.

Could you help me to debug this ?

http://69.90.160.65/~o110334/

thanks

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It seems to have something to do with a width and maybe positioning. If I put a position: relative on your id="main-inner" and EITHER on the id="content" I change the left margin from 240px to 239px OR change the id="sidebar-left" width from 240px to 239px it seems to work. While this may not be the final solution you seek, it does seem to indicate that it is some interaction in the width of elements and the margins that is causing your issue.