CSS dropdown menu crisis with IE 7...

I have a set up dropdown menus that contains images, and everything worked perfectly in Firefox, as usual.. and at first it wouldn't work with IE6 either, until i applied a fix.. and i've even tried a fix that is supposed to work with IE 7, but doesn't seem to be. below is the code i added in:

/* clear fix */
/* --------------------- */

.clearfix:after {content: "."; display: block; height: 0; clear: both; visibility: hidden;}
.clearfix {display: inline-table; min-height:1%;}
/* Hides from IE-mac \*/
* html .clearfix {height: 1%;}
.clearfix {display: block;}
/* End hide from IE-mac */

and the site, where you can see the code, etc is:
http://www.mosaicfound.org/NEW/home/home.php

I don't know that this code is perfect, but it hadn't worked for IE 7 yet, and there are still spaces around the menu bars, as you'll see if you have IE 7 on your computer and visit the webpage below.