After further investigations, the problem seems to be the use of the GCJ based java. Indeed by switching environment to sun java (for instance with sudo update-alternatives --set java /usr/lib/jvm/java-1.5.0-sun/jre/bin/java), the package runs without any problem. 'I don't see why everyone depends on me. I'm not dependable. Even I don't depend on me, and I'm me.' (Interesting Times)