Sorry, that the header is garbled - should be "Re: 2.0.0 Beta2: unable to add Jboss EJB3 Libraries [error]" .
But the problem has gone after an eclipse restart. sorry for the convience.
I would want to try out ejb3 (http://wiki.jboss.org/wiki/Wiki.jsp?page=StarterSkeletonEclipseProject)
I ran in exactly the same problem.
Seems to me that at least my config (JBoss AS 4.0.5 and JBoss IDE 2.0.0 Beta2) doesn't work in this context.