System.exit(1) not killing java process on solaris

[Gaurav Bhatia]

I have a Java process running and exchanging messages over ems to other components and exposing RMI services.
On an exception from ems server (i.e. when EMS connection is lost), i call System.exit(1).

There is a shutdown hook that gets called, this closes the ems connections.
After this the process keeps on running and doesn't die.

Any thoughts what could be stopping it from getting crashed?

Thanks,