jQuery fade buttons not working on single.php

Using the following jQuery code my fade menu buttons work fine on index.php – but when I click the title & go to single.php the fade doesn’t work.

I can see no reason for it to fail as it calls the same header.php that index.php does.. Any ideas (without rewriting the code please, as this is what I am used to!) ?

<script type="text/javascript" src="jquery-1.3.2.min.js"></script>
<script type="text/javascript">
	jQuery(document).ready(function() {
		jQuery('.static,.home,.about,.services,.pricing,.email,.contact,.portfolio').append('<span class="hover"></span>').each(function () {
	  		var jQueryspan = jQuery('> span.hover', this).css('opacity', 0);
	  		jQuery(this).hover(function () {
	    		jQueryspan.stop().fadeTo(800, 1);
	 		}, function () {
	   	jQueryspan.stop().fadeTo(800, 0);
	  		});
		});
	});
</script>