invalid (x)html produced by rss feed

Hi, yesterday, I set up my web page so that the RSS feed is displayed, so I was pleased when I saw the information there today. However, when I used W3C's validator tool to check the code was valid, I discovered that there were errors in the HTML code produced by the feed:
< b >foo goal:< b >
instead of:
< b >bar goal:< / b >
That is: the closing < / b > is actually an opening < b > [Ignore the spaces - they're just there because I can't work out how to make it display the tags as is.].