I just find another bug in Ubuntu Intrepid. This post said it will occur if you install both Sun-JRE and opensource OpenJDK. The error message is missing of libmawt.so
Can't load library: /usr/lib/jvm/java-6-openjdk/jre/lib/i386/xawt/libmawt.so
There is already reported bug in Launchpad. Sadly, it was marked as 'Won't fix'. Anyway, the workaround is switching to Sun-JRE instead.
sudo update-java-alternatives -s java-6-sun
I'm starting to believe that Ubuntu's two-release-a-year is too frequent.