BTW I am running the JBoss IDE with Build id: 2.0.0.Beta2. and Tomcat 5.5.12.
The JSF portion of JBoss IDE is actually from eclipse. It seems that their module artifact adapter (which turns a selection into something that can be run on a server) is incomplete.
That error message only appears if an "artifact" is found, but it's module is empty. This, from my experience with the code, should only happen due to a programming oversight or error.
Again, this would be a bug for eclipse and whichever project the JSF component is in. I assume it's webtools but am not sure.