WordPress MU

I'm running 6 blogs, and this morning, one of them just randomly decided to break. The RSS feed (http://domain.com/broken_blog/feed) is corrupt. When I view the source of the broken blog in comparison to a working blog, the headers differ in the following way:

Broken:

<?xml version="1.0" encoding="UTF-8"?>
<!-- generator="wordpress/wordpress-mu-1.2.3-2.2.1" -->
<rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	>

Working:

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="http://domain.com/~d/styles/rss2full.xsl" type="text/xsl" media="screen"?><?xml-stylesheet href="http://domain.com/~d/styles/itemcontent.css" type="text/css" media="screen"?><!-- generator="wordpress/wordpress-mu-1.2.3-2.2.1" --><rss xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:dc="http://purl.org/dc/elements/1.1/" version="2.0">

Why would this inconsistency be happening? I'm thinking that an author on the broken blog may have submitted content that caused this error, but I haven't fully figured this out. Any ideas? Thanks.

WPMU 1.2.3

Turns out the problem was an author error. The author did a copy-paste from MS Word into the WP editor with text that contained one of MS's special quote (') characters. The headers were different probably because the content of the RSS feed was corrupt.

Change the post title; problem solved.

Sorry for the rushed post.

Glad you got it fixed. :)