i dont think a jboss client will talk to a jboss server started with the jdk. or have you compiled the server with gcj? i made some tests concerning gcj/jdk rmi interoperability (using the latest gcj (3.4) from cvs) read the last comment in my bug-report (and try the little test-suite i have provided). http://gcc.gnu.org/bugzilla/show_bug.cgi?id=7938 did anyone have a different experience? norbert