Following Problem. I got a a4j-portlet with richfaces 3.0.1 running in Portal 2.6.2. All fine so far.
Now I develop a Seam Application with newest RichFaces 3.13.
When I deploy both the Portlet and the Seam Application on the same JBoss AS, I got exceptions, because the a4j-portlet tries to use the 3.13 Jars. And because the RichFaces API changed from 3.01 to 3.13 i have a lot of ClassNotFound exceptions.