IE 7 will not show animated GIF and then redirect... no animation is shown

it seems that if i show an animated GIF and then use

top.location.href = "http://...";

to do a redirect, Firefox or Chrome will both show the animated GIF fine, but IE 7 will show the animated GIF only for its first frame. It is not animated at all.

the code is like this:

<img id="progressLoop" src="progressLoop.gif" style="visibility:hidden" />

<select onchange="go()">
	<option value="1">1</option>
	<option value="2">2</option>
	<option value="3">3</option>
</select>

<script>
function go() {
	document.getElementById('progressLoop').style.visibility = 'visible';
	top.location.href = 'http://www.somesite.com/test_redirect.php?i=' + Math.random();
}
</script>

Code (markup):

it is the same if i use display: none instead of visibility. Further, if i use width: 0, and then set it to 16px before redirect, it is the same thing: no animation on IE 7.

the only way I can get it to work is by using setTimeout(redirect, 1000) to do the redirection so that there is a 1 second delay. Unfortunately, I need to do this using FBJS which is Facebook's javascript and they have no setTimeout() support at all. I wonder if this can be done on IE 7 without setTimeout() at all? Thanks very much.