Switching between RI and MyFaces

[Jefferson Parke]

I'm trying to find an easy way to switch back and forth between RI and MyFaces.  As I understand it, it can be as easy as replacing jsf-api.jar and jsf-impl.jar with myfaces-api.jar and myfaces-impl.jar and vice versa.  For me, when I try to switch from MyFaces back to RI (not for good mind you! :)) I replace the jars as described and for some reason I get the following exception:

2006-09-25 20:31:04 StandardContext[/MyProject]Error configuring application listener of class org.apache.myfaces.webapp.StartupServletContextListener
java.lang.ClassNotFoundException: org.apache.myfaces.webapp.StartupServletContextListener
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1340)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1189)
    at org.apache.catalina.core.StandardContext.listenerStart (StandardContext.java:3775)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4343)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1083)
    at org.apache.catalina.core.StandardHost.start (StandardHost.java:789)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1083)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:478)
    at org.apache.catalina.core.StandardService.start (StandardService.java:480)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:2313)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:556)
    at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:287)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:425)

I've checked web.xml and faces-config.xml and neither references MyFaces.  My understanding is that myfaces_core.tld in myfaces-impl.jar contains the reference to StartupServletContextListener but clearly that tld is of no consequence because myfaces-impl.jar is not in my classpath (otherwise it would have also found StartupServletContextListener to begin with).

Can anyone suggest other files that may reference MyFaces, and StartupServletContextListener in particular?  Is my understanding about how to switch back and forth correct?

Thanks for any help.

- Jeff