As RichFaces 3.1 is targeted at JSF 1.1, you won't get ViewExpiredExceptions generated when using it with JSF 1.2. Fortunately there is an easy workaround. Add to your web.xml:

<context-param>
  <param-name>com.sun.faces.disableVersionTracking</param-name>
  <param-value>true</param-value>
</context-param>