Using Prototype .update not working right in IE7

Question

Im trying to update an image after the user clicks it, but IE7 seems to load the image in the Dom right, but doesnt display the image. Firefox has no issue, and IE7 doesnt display an error and using IE Developer Toolbar tells me that the image is properly replaced, but IE7 Doesnt actually display the image, its like the image is there, just invisible. Any suggestions?

JS:

function togglePS5RepLocatorBox() {
    if ($('PS05RepLocatorBox').className == "PS05RepOpen") {
        $('PS05RepLocatorBox').className = "PS05Rep";
        $('PS5repButtonLink').update('<img id="PS5repButton" src="images/PS05/PS5ContactRepClosed.png" alt="Contact Your Rep" />');                 
    } 

        else {
            $('PS05RepLocatorBox').className = "PS05RepOpen";
                $('PS5repButtonLink').update('<img id="PS5repButton" src="images/PS05/PS5ContactRepOpen.png" alt="Contact Your Rep" />');
    }
}

HTML:

<div id="PS05RepLocatorBox" class="PS5RepLocatorBox PS05Rep">    
    <a id="PS5repButtonLink" href="/index.html" onclick="togglePS5RepLocatorBox(); return false;">
           <img id="PS5repButton" src="images/PS05/PS5ContactRepClosed.png" alt="Contact Your Rep" />
    </a>
</div>