Odd jQuery UI Error

I'm attempting to use the jQuery UI Tabs module, but whenever I attempt to do so, I get the following error in my console:

Uncaught TypeError: Object #<an Object> has no method 'tabs'

I followed the demo's source down to the letter, and I still can't get it to work.

I'm loading the CSS locally and the JS from the Google CDN, and Chrome's Developer Tools are telling me that the browser got a 200 OK for each JS and CSS file.

Can anyone shed some light on this?

Thanks in advance!

Per request, I'm also adding my code:

<div id="tabs">
    <ul>
        <li><a href="#tabs-1">TrafficLight!</a></li>
        <li><a href="#tabs-2">countr</a></li>
        <li><a href="#tabs-3">Future projects</a></li>
    </ul>
    <div id="tabs-1">
        <p><b>TrafficLight!</b> is an application that will temporarily turn your iPhone's screen red, yellow, or green. It's useful for providing instant, easy-to-understand feedback to anyone, especially a public speaker.</p>
        <p><b><a href="#">Download on the App Store</a></b></p>
    </div>
    <div id="tabs-2">
        <p><b>countr</b> is a basic counting application. You can use it to count baseball pitches, money, hats, anything!</p>
        <p><b><a href="#">Download on the App Sto开发者_C百科re</a></b></p>
    </div>
    <div id="tabs-3">
        <p><i>Coming soon... ;)</i></p> 
    </div>
</div>

Whoops, forgot this part of the code:

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.js"></script>
<script type="text/javasctipt" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/jquery-ui.js"></script>
<script type="text/javascript">
$(document).ready(function() {
    $("#tabs").tabs();
});
</script>
<link rel="stylesheet" href="jquery-ui-1.8.4.custom/css/ui-darkness/jquery-ui-1.8.4.custom.css">

I found your problem. In your jQuery UI script tag you have "type='text/javasctipt'" which "javascript" is misspelled.