The JVM used is a Reference one :
java version "1.2.2"
Classic VM (build JDK-1.2.2-W, native threads, sunwjit)

Two test actors based on a Java product, a manager and an agent, are
interacting.
After a time varying from 2 to 500 hours, I get a JVM crash on agent side as
well as a core file (both stack and core attached).
The JVM is used with JIT ON and native threads.
See Comments.