Java Development Tools

Hi,
i have some trouble, deploying my BC4J project from JDeveloper 903 to OC4J 903.
Deploying the Servermodule the first time it is no problem, but then i added
some new ViewObjects to my ServerModule(i assigned them to the DataModel in the
ServerModule Wizard) and then i redeploy the ServerModule again.
I did not change anything except adding the ViewObjects. But when i start my Application
accessing the ServerModule it fails with the Exception below.
The first time when this happens i thought it was my mistake and i rebuild my
complete ServerModule from the scratch, but now it happen again and i can not reconstruct
why this happened. Can some one help me to avoid this in future?
Can someone explain me what happened?
and can someone help me to keep my project running without rebuilding it from scratch?

Thank you for your help

Regards Mirko

JBO-30003: The application pool (de.orb.server.ServerModule) failed to checkout an application module due to the following exception:

oracle.jbo.ApplicationModuleCreateException: JBO-25222: Unable to create application module.
void oracle.jbo.ApplicationModuleCreateException.<init>(java.lang.Exception)
ApplicationModuleCreateException.java:64

oracle.jbo.ApplicationModule oracle.jbo.client.remote.ejb.ApplicationModuleProxy.createClientAdapter(oracle.jbo.common.remote.ejb.RemoteApplicationModule, java.util.Hashtable)
ApplicationModuleProxy.java:151

oracle.jbo.ApplicationModule oracle.jbo.client.remote.ejb.ApplicationModuleProxy.create(javax.ejb.EJBHome, java.util.Hashtable)
ApplicationModuleProxy.java:82

oracle.jbo.ApplicationModule oracle.jbo.client.remote.ejb.AbstractApplicationModuleHomeImpl.createRemoteEJBApplicationModuleProxy()
AbstractApplicationModuleHomeImpl.java:47

oracle.jbo.ApplicationModule oracle.jbo.client.ejb.ApplicationModuleHomeImpl.create()
ApplicationModuleHomeImpl.java:74

oracle.jbo.ApplicationModule oracle.jbo.common.ampool.DefaultConnectionStrategy.createApplicationModule(java.util.Hashtable)
DefaultConnectionStrategy.java:135

oracle.jbo.ApplicationModule oracle.jbo.common.ampool.DefaultConnectionStrategy.createApplicationModule(oracle.jbo.common.ampool.SessionCookie, oracle.jbo.common.ampool.EnvInfoProvider)
DefaultConnectionStrategy.java:76

java.lang.Object oracle.jbo.common.ampool.ApplicationPoolImpl.instantiateResource(java.util.Properties)
ApplicationPoolImpl.java:1767

java.lang.Object oracle.jbo.pool.ResourcePool.createResource(java.util.Properties)
ResourcePool.java:315

oracle.jbo.ApplicationModule oracle.jbo.common.ampool.ApplicationPoolImpl.doCheckout(oracle.jbo.common.ampool.SessionCookie)
ApplicationPoolImpl.java:1394
...
## Detail 0 ##

java.lang.ClassNotFoundException: de.orb.server.client.ejb.beanmanaged.ServerModuleClient
java.lang.Object java.net.URLClassLoader$1.run()
URLClassLoader.java:200
....