We have a bug report for Python 1.5.2 that says building with threads enabled causes a core dump with the interpreter is started. #110650: http://sourceforge.net/bugs/?func=detailbug&bug_id=110650&group_id=5470 I don't have access to an HP-UX box on which to text this problem. If anyone does, could they verify whether the problem exists with the current code? Jeremy