I created a Seam project using the Seam Web Project wizard. Then I had 4 projects: war, ear, ejb and test. Since we separate Eclipse's project-setting-files from the source I replaced all folders with linked folders.

As soon as I replaced the EAR-project's folders "EarContent" and "resources" by directories outside the workspace I wasn't able to display the "J2EE Module Dependencies" page in the ejb's or war's project settings. Therefore I couldn't add important jars like jboss-seam.jar to the ejb or war. And this prevents a build.