Glassfish Admin Console causes core dump openjdk6

[Phill]

I'm trying to get Glassfish 3.1 running under openjdk6, it seems to start ok but when I access the Admin Console in a web browser it crashes with:

# 
# A fatal error has been detected by the Java Runtime Environment: 
# 
# SIGSEGV (0xb) at pc=0x0000000802565d34, pid=96056, tid=35286523776 
# 
# JRE version: 6.0-b20 
# Java VM: OpenJDK 64-Bit Server VM (17.0-b16 mixed mode bsd-amd64 ) 
# Problematic frame: 
# 
[error occurred during error reporting (printing problematic frame), id 0xb] 

# An error report file with more information is saved as: 
# /usr/home/glassfish/glassfish3/glassfish/domains/domain1/config/hs_err_pid96056.log 
# 
# If you would like to submit a bug report, please visit: 
# http://java.sun.com/webapps/bugreport/crash.jsp 
# 
The DAS was stopped. 

I tried to open a bug report with Glassfish but it got promptly closed as FreeBSD is not a supported OS.
http://java.net/jira/browse/GLASSFISH-14916
http://java.net/jira/secure/attachment/23662/hs_err_pid96056.log

It does however run under diablo-jdk-1.6 without crashing and glassfish 3.0 also runs ok on openjdk6.
Any ideas?
Phill