i removed jsf-api and jsf-impl jars from richfaces-demo.war and works now.
If you look at:
you can see there:
Ready-to-Deploy war RichFaces Demo:
* [J2EE Containers - Tomcat 5.5.x, JBoss 4.0.x and other]
* [Tomcat 6.0.x]
* [ JavaEE 5 Containers - JBoss 4.2.0 and other]
So, the answer is right in the text.