ok, did not know that. I tried now a full publish and it does not work either. I don't know what kind of information do you want, since I don't get any error message. According to the plugin it gets published but it is not.
When I click on explore, the following folder will be opened:
E:\Projekte\eclipse jboss\.metadata\.plugins\org.jboss.ide.eclipse.as.core\JBoss_5.1_Runtime_Server1284987388425\deploy\HelloWorld_webfr.war
The classes and libraries are in the war file as it should be.