I have been getting some weird errors when I upgrade jQuery from 1.4.4 to 1.5.1. Maybe you guys can explain what I need to change or why the new version is not working.
In 1.4.4 I have the following code 
<div class="navlink home" data-link="home">
    <span class="top">Home</span>
</div>
<div id="index-03">
</div>
<div class="navlink resume" data-link="resume">
    <span class="top">Resume</span>
</div>
<div id="index-05">
</div>
<div id="index-06">
</div>
<div class="navlink portfolio" data-link="portfolio">
    <span class="bottom">Portfolio</span>
</div>
JS:
$(".navlink").hover( 
    function () { 
        $(this).delay(100).animate({backgroundPosition: "-100% 0"}, 400);
        $(this).find("span").css("textDecoration","underline");
    },
    function () {
        $(this).queue("fx", []);
        $(this).animate({backgroundPosition: "0% 0%"}, 400);
        $(this).find("span").css("textDecoration","none");
    }
);
Which works just fine.
but when I switch jQuery versions by changing this line in my header from 
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>
to 
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js"></script>
The above code quits animating and the background image just disappears. 
Here is a jsFiddle that shows what's happening just change the jQuery version on the side between 1.4.4 and 1.5.1
http://jsfiddle.net/fUXZ4/ -- 1.4.4
http://jsfiddle.net/3APCd/ -- 1.5.1
Here is a video of exactly what is happening to me: http://img.zobgib.com/2011-03-07_1905.swf