It looks like the code that generates link from keywords beginning with "<a href="http://" "="" rel="nofollow">http://" conflicts with the code that generates links in the Discussions page. For example, take the message title:

http://java.sun.com and J2EE SDK screwed up ?

This generated the nested links:

<td valign="top"><font size="2"><a href="thread.jsp?thread_id=22803" class="undecorated"><a href="http://java.sun.com" target="_blank">http://java.sun.com> and J2EE SDK screwed up ?</a></font></td>