We have found the issue.
The problem was:
I imported all my projects as "existing maven project". Then - somehow -, the org.eclipse.wst.common.component file under the ear project's .settings directory referenced for the projects - which should have been packaged (zipped) into the ear's lib directory - as resource instead of maven reference.
Problem:
<dependent-module archiveName="wicket-core-2.0.1-SNAPSHOT.jar" deploy-path="/lib" handle="module:/resource/com.doctusoft.web.wicket-core/com.doctusoft.web.wicket-core">
<dependency-type>uses</dependency-type>
</dependent-module>
Solution:
I replaced it to this:
<dependent-module archiveName="wicket-core-2.0.1-SNAPSHOT.jar" deploy-path="/lib" handle="module:/classpath/var/M2_REPO/com/doctusoft/web/wicket-core/2.0.1-SNAPSHOT/wicket-core-2.0.1-SNAPSHOT.jar">
<dependency-type>uses</dependency-type>
</dependent-module>
No it's packed correctly and works fine!
Thanks a lot!
z.