rollover links won't actually link in IE

http://www.frontendaudio.com/CAD-M179-Condenser-Microphone-p/1637.htm

is a page in question.

The buttons in question are the Video Clips and Audio Clips.

You can rollover them and see the links actualy appear in the status bar, and the links work fine in firefox, but nothing happens when clicked in IE.

Here is the CSS making it happen

.audio_clips_tab {
font-size:21px;
padding:5px;
padding-bottom:0px;


display: block;
width: 145px;
height: 31px;
background: url(../images/audio_png.png) no-repeat 0 -31px;


}

.audio_clips_tab:hover {
font-size:21px;
padding:5px;
padding-bottom:0px;

background-position: 0 0;


}

In IE6 you can see that there is something that is actually over the link causing it not to work. There are JS errors in IE6, IE7, and IE8 but the links do work in IE8.