Sliding door tabs not working for me

[Space Goat]

Edit: Never mind, I have decided not to use sliding doors. The admins may delete this thread if they wish; I'm sorry for wasting time.

I'm currently redesigning my site, Hypersyllogistic, from a table-based layout to a pure CSS layout.

My progress so far appears here.

I am trying to implement Dynamic Drive's CSS Sliding Doors technique, but the effort isn't going well. Can anyone tell me what I'm doing wrong?

Here is my CSS code for the menu:

#navigation {float: left; width: 100%; position: relative: bottom: 0; z-index: 2}

#navigation ul {list-style: none; font-size: 0.7em; text-align: center; font-weight: bold; padding: 0; margin: 1.06em 0 0; border: none}

#navigation li {display: inline}

#navigation a {float: left; height: 32px; line-height: 29px; text-decoration: none; color: white; background: url(../images/deftableft.png) no-repeat left top}

#navigation a span {float: left; display: block; height: 32px; line-height: 29px; text-decoration: none; color: white; background: url(../images/deftabright.png) no-repeat right top}

#navigation a:hover {background: url(../images/deftabhovleft.png) no-repeat left top}

#navigation a:hover span {display: block; background: url(../images/deftabhovright.png) no-repeat right top}

Here is my HTML code:

<div id="navigation">
        	<ul><li><a href="http://www.hypersyllogistic.com/" title="Find the latest screeds, and vote in the most current poll."><span>Home</span></a></li><li><a href="http://www.hypersyllogistic.com/about.php" title="The purpose and mission of Hypersyllogistic."><span>About the Site</span></a></li><li><a href="http://www.hypersyllogistic.com/screedarchives.php" title="A collection of my screeds that have appeared on the front page."><span>Screed Archives</span></a></li><li><a href="http://www.hypersyllogistic.com/writings.php" title="An archive of my past writings and papers."><span>Writings</span></a></li><li><a href="http://www.hypersyllogistic.com/links.php" title="A directory of favorite links."><span>Links</span></a></li><li><a href="http://www.hypersyllogistic.com/photogalleries.php" title="Photographs I've taken of various interesting locales."><span>Photo Galleries</span></a></li><li><a href="http://forums.hypersyllogistic.com/index.php?automodule=blog" title="Share your thoughts, and read those of others."><span>Blogs</span></a></li><li><a href="http://forums.hypersyllogistic.com" title="Sound off on whatever you want, because your opinion matters!"><span style="color: #FFFF00;">Forums</span></a></li></ul>
      </div>