… might be due to a bug in Sun Java 6. Try upgrading to Java 6 Update 10 release candidate (also known as ‘beta’) or using a different Java VM such as IBMs or GNU. Worked for me.

Bug reported in Feb 2008 and Bug reported in Oct 2008 at Sun (note: they are marked as ‘fix delivered’ but that includes beta releases such as the 6u10RC linked above.