I just checked this on a brand new Vista64 laptop with IE7 and I did not experience the same problem. Please clear your temporary internet files and see if it's okay afterwards. If not, try reinstalling IE7. Let me know how that works out.

Regards,
Jim

/* clearing & floating */
/* http://www.positioniseverything.net/easyclearing.html */
/* http://www.456bereastreet.com/archive/200603/new_clearing_method_needed_for_ie7/#comment28 */
.clearfix { display: inline-block }  
.clearfix { display: block }         
* html .clearfix { height: 1% }      
 
 
* html .floatbox { width:100% }
 
 
.ie_fix_floats { 
    width: 100%;
    padding: 0 1px 0 1px;   
    margin: 0 -1px 0 -1px;  
    overflow: hidden;
}

The User Agent String Utility makes Internet Explorer 7 appear to be Internet Explorer 6 to sites that mistake Internet Explorer 7 for an out-of-date version. It is intended to be a temporary workaround until the site owner has addressed the issue. Because the browser is still Internet Explorer 7, use of this tool is not guaranteed to solve functionality or rendering issues on these sites. You should contact the site owner if this utility allows you to properly use their site in IE7.