If there are special characters in the Blog's title, they are not correctly escaped in the RSS feeds.
Test Case Example: http://test.dcostanet.net/wordpress/ The title has been set to
Test blog ; & ” ‘ ; < > ! special chars
In the RSS feed. http://test.dcostanet.net/wordpress/?feed=atom the title shows up as
<title>Test blog ; & " ' ; < > ! special chars</title>
The special characters (double and single quote, and the inequality signs) need to be escaped. There is a similar problem with the other RSS feeds. http://test.dcostanet.net/wordpress/?feed=rss2
In the html part of the document http://test.dcostanet.net/wordpress/ the special characters are escaped correctly
<title>Test blog ; & ” ‘ ; < > ! special chars </title>
This bug applies to version 1.5.1.2 (Trac reports it as 1.5.2) - a bug in trac maybe?