>The changes are already in the current 3.4 tree >(see boehm-gc/mark.c). Blush! :-) I've re-run my tests and it still crashes, though perhaps this is a different problem? See at the bottom of the bug-report for details on my quick debug session. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10746 Øyvind