[TYPO3-english] pop-up menus not working in IE

[Miguel Guerrero - Tu3w]

Hi folks,
we're trying to implement a website using pop-up menus with CSS. The code works fine outside TYPO3:

http://caq.edu.ec/2010/menus/menuvertical.html

http://caq.edu.ec/2010/menus/menuhorizontal.html

When implementing it into TYPO3, all works fine, except with IE (Internet Explorer, all versions):

http://caq.edu.ec/2010/

Any ideas what is causing the issue and how could we solve it?

Thanks,
Miguel