If your feed has these XML tags in it:
Code:
<o:p>(some text)</o:p>
It is very likely that your feed will be considered invalid by FeedBurner, Feed Validator, and possibly many other places to which you want your feed properly distributed. The result is that FeedBurner will stop updating its version of your feed until the validation problem is repaired.
The <o:p> tag is usually introduced by a copy-paste of original text from Microsoft Word or another Office application; this tag originates in a Microsoft XML "namespace," or definition of a custom set of tags used for XML markup. The best way to avoid this problem is to avoid composing and copying content from Word into your blogging tools. If you still want to use content found in Office applications, a common trick for removing extraneous code is to "clean" copied text by pasting it into a plain text editor, such as Notepad (Windows) or TextEdit (Mac) and the copying the newly cleaned text before pasting it into your blogging application.
In general, using word processing applications to compose blog posts can lead to unexpected results (such as this one). We recommend that you compose new posts in a text editor recommended or provided by your blog platform publisher only.