Alexej, your third option worked. And after restarting Eclipse, now it works even without setting the absolute folder!
Denis, the file content is:
<?xml version="1.0" encoding="UTF-8"?>
<project-modules id="moduleCoreId" project-version="1.5.0">
<wb-module deploy-name="smsurbano">
<wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/>
<wb-resource deploy-path="/" source-path="/src/main/webapp"/>
<property name="context-root" value="smsurbano"/>
<property name="java-output-path" value="/smsurbano/target/classes"/>
</wb-module>
</project-modules>
Before, I had another line in the file (see thread http://community.jboss.org/thread/162518?tstart=0) which was always recreated when I right-clicked on the project and chose Maven>Update Project Configuration. Now I deleted it again and this time it was not recreated (due to the restart of Eclipse?). Maybe this was the reason that the path was not resolved correctly.
Thanks,
Ulrich