Moving from Struts 1.0b1 to Struts 1.0b3

[Graeme Miller <Gr...@AdvantageGroup.co.nz>]

Currently having a problem with migrating code from using Struts 1.0b1 to
Struts 1.0b3

Everything seems to work fine apart from the fact that the validate methods
on our form beans (ie subclasses of org.apache.struts.action.ActionForm) no
longer get called successfully.  I have had a look through the release notes
and cannot find any reasons why these methods would no longer work.  

Any ideas people?  The following error is what gets thrown in the tomcat
log.

java.lang.ClassCastException
        at
org.apache.tomcat.facade.RequestDispatcherImpl.forward(RequestDispatcherImpl
.java, Compiled Code)
        at
org.apache.struts.action.ActionServlet.processValidate(ActionServlet.java,
Compiled Code)
        at
org.apache.struts.action.ActionServlet.process(ActionServlet.java, Compiled
Code)
        at
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:509)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java,
Compiled Code)
        at org.apache.tomcat.core.Handler.service(Handler.java, Compiled
Code)
        at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java, Compiled
Code)
        at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java,
Compiled Code)
        at
org.apache.tomcat.core.ContextManager.service(ContextManager.java, Compiled
Code)
        at
org.apache.tomcat.service.connector.Ajp12ConnectionHandler.processConnection
(Ajp12ConnectionHandler.java, Com
piled Code)
        at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java,
Compiled Code)
        at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java,
Compiled Code)
        at java.lang.Thread.run(Thread.java:479)

Thanks in advance.
Graeme.