After installing version 4.0.2-12.EL4 of the gcj4 compiler, jdom no longer builds. This is a known gcj bug enumerated in Red Hat bz #175569(https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=175569). There is a work-around.
A patch has been generated with a work-around until the compiler gets fixed.