[TYPO3] empty <link> in rss.xml source?

[Bing Du]

Hi,

typo3 4.0.6
tt_news 2.4.0

I noticed that some news items in the source of
http://www.somesite.some.edu/rss.xml have valid URLs between <link> and
</link> like this:

<item>
<title>Engineering contributes another WISE intern</title>
&#8722;
	<link>
http://www.somesite.some.edu/news/news-article/article/953.html
</link>
&#8722;
	<description>
For the third consecutive year, a student from the College of Engineering
participated in the...
</description>
<category>CoE In The News</category>
<category>ME News</category>
<category>CoE News Articles</category>
<category>CoE News Preview</category>
<pubDate>Wed, 01 Aug 2007 09:27:00 -0500</pubDate>
</item>

However, other news items have empty links like this one.  It only has a
closing <link/>

<item>
<title>Engineers share in economic development grants</title>
<link/>
<description/>
<category>CoE In The News</category>
<pubDate>Thu, 05 Jul 2007 12:39:00 -0500</pubDate>
</item>

Anybody else ever seen this too and know why?

Thanks much in advance for any insight.

Bing