defunct /zombied java processes (Linux)

Has anyone hit a problem with IDEA (any version) locking up and then when you kill the process, the Java process becomes defunct/zombied, and prevents any further instances of Idea running?

I get this a lot on Redhat 9, 2-3 times a week, and nothing can kill the damned process except a reboot.

Any suggestions of things to try or fixes to make?

Nick