It looks like a JRE bug on Windows. Which exact version of Windows are you using? Looking at your stactkrace the JRE version appears to be Sun Java 1.6.0_21. Can you try upgrading to a latest update of Sun Java 1.6 (although I don't expect it to be fixed in the latest versions if it isn't in the 21 update). But give it a try. The bug reference is here http://bugs.sun.com/view_bug.do?bug_id=6230761