Well I've never had access to an HP machine, so I've never tested it on HPUX. Does libjava.so actually exist in /opt/java/lib? Most of the java distrubutions that I've worked with actually have libjava.so located in a subdirectory of lib/java. On my solaris machine it's located in the jdk1.1.8/lib/sparc/native_threads directory. On redhat 6.2 it's located in the jdk1.1.8_v1/lib/i686/native_threads directory. Geneerally it follows the pattern of lib/architecture/threads_version (green or native). You should also upgrade your jdk to 1.1.8, as I think that the 1.1.7 version had some threading problems. Make sure that you also get a native threads jdk version.