Picture not showing in "Get Info" for Podcast

Question

I've just created a podcast and uploaded it. The audio works just fine, but for some reason the image that I want to associate with the file doesn't show up in "Get Info". Anyone know what may be causing this?
The .xml for the podcast follows:
<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
<channel>
<title>Teaching American History Podcast</title>
<link>http://www.teachingamericanhistory.org/podcasts/</link>
<description>The Teaching American History Podcast is based on programs for teachers sponsored by the Ashbrook Center at Ashland University, Ashland, Ohio. These seminars are designed to encourage teachers to seriously examine significant events in American history in light of the principles of the American founding, and also to encourage the use of primary source materials in the classroom. The seminars, which include both lecture and discussion, are taught by leading scholars in their field from throughout the nation.</description>
<copyright>Copyright 2006, Ashbrook Center for Public Affairs</copyright>
<lastBuildDate>Tue, 24 Jan 2006 07:00:00 EST</lastBuildDate>
<itunes:summary>The Teaching American History Podcast is based on programs for teachers sponsored by the Ashbrook Center at Ashland University, Ashland, Ohio. These seminars are designed to encourage teachers to seriously examine significant events in American history in light of the principles of the American founding, and also to encourage the use of primary source materials in the classroom. The seminars, which include both lecture and discussion, are taught by leading scholars in their field from throughout the nation.</itunes:summary>
<itunes:author>Ashbrook Center for Public Affairs</itunes:author>
<itunes:keywords>Ashbrook Center, Teaching American History, Education, History, American History</itunes:keywords>
<image>
<url>http://www.ashbrook.org/images/logo_head.jpg</url>
<title>Ashbrook Center for Public Affairs</title>
<link>http://www.teachingamericanhistory.org/podcasts/</link>
</image>
<itunes:category text="Education"/>
<itunes:owner>
<itunes:email>[email protected]</itunes:email>
<itunes:name>Ashbrook Center for Public Affairs</itunes:name>
</itunes:owner>
<itunes:image href="http://www.ashbrook.org/images/logo_head.jpg"/>
<item>
<title>"Causes of the Civil War" (Session 1), February 12, 2005</title>
<description>Few other questions in American history have generated more controversy than "What Caused the Civil War?" That conflict preserved the United States as one nation, indivisible and abolished the institution of slavery that for more than four score years had made a mockery of American claims to stand as a republic of liberty, a beacon of freedom for oppressed peoples in the Old Word. But these achievements came at the great cost of more than 629,000 lives and vast destruction of property that left large parts of the South a wasteland. Could this terrible war have been avoided? Who was responsible for the events that led to war? Could the positive results of the war (Union and Freedom) have been achieved without war? How have participants in the war and historians answered these questions over the five generations since the war ended? James M. McPherson is the George Henry Davis '86 Professor of History at Princeton University and is widely acclaimed as the leading historian of the Civil War. He is the author of Battle Cry of Freedom: The Civil War Era, which won the Pulitzer Prize in history in 1989, as well as many other books on Lincoln and the Civil War era. This is the first in a two-part series.</description>
<pubDate>Tue, 24 Jan 2006 07:00:00 EST</pubDate>
<link>http://www.teachingamericanhistory.org/podcasts/</link>
<guid>http://www.teachingamericanhistory.org/podcasts/mcpherson05-02-12session1.mp3</guid>
<itunes:summary>Few other questions in American history have generated more controversy than "What Caused the Civil War?" That conflict preserved the United States as one nation, indivisible and abolished the institution of slavery that for more than four score years had made a mockery of American claims to stand as a republic of liberty, a beacon of freedom for oppressed peoples in the Old Word. But these achievements came at the great cost of more than 629,000 lives and vast destruction of property that left large parts of the South a wasteland. Could this terrible war have been avoided? Who was responsible for the events that led to war? Could the positive results of the war (Union and Freedom) have been achieved without war? How have participants in the war and historians answered these questions over the five generations since the war ended? James M. McPherson is the George Henry Davis '86 Professor of History at Princeton University and is widely acclaimed as the leading historian of the Civil War. He is the author of Battle Cry of Freedom: The Civil War Era, which won the Pulitzer Prize in history in 1989, as well as many other books on Lincoln and the Civil War era. This is the first in a two-part series.</itunes:summary>
<itunes:explicit>no</itunes:explicit>
<itunes:duration>01:41:33</itunes:duration>
<itunes:keywords>James McPherson, Civil War, Teaching American History, Ashbrook Center, History, American History</itunes:keywords>
<enclosure url="http://www.teachingamericanhistory.org/podcasts/mcpherson05-02-12session1.mp3" type="audio/mpeg"/>
<itunes:category text="Education"/>
</item>
</channel>
</rss>
<END OF XML>
I have double-checked and the image file is online.
Any help would be greatly appreciated!
  Windows 2000  

Answer 1

Artwork for the individual episodes that show during playback comes from an ID3 tag embedded inside the MP3 file - just like a regular song.