Sorry, but as stated the documentation (and the examples) is only for the stable line, not for 3.0. You will need to change the classpath settings in build.xml to get it to work. (jar-files have moved, been renamed and new one come forth between releases), your error probably has to do with concurrent.jar.
Thanks Peter! It is what you said. In fact I ran all the examples on 3.0 and that was the only problem I had.