An important fix has been committed to the ptlib SVN to fix a bug in windows where nonAutoDelete threads where autoDeleting causing strange segfault at the end of a call. If you are experiencing the issue please apply this patch. http://opalvoip.svn.sourceforge.net/viewvc/opalvoip/ptlib/trunk/src/ptlib/ms os/win32.cxx?r1=26095 <http://opalvoip.svn.sourceforge.net/viewvc/opalvoip/ptlib/trunk/src/ptlib/m sos/win32.cxx?r1=26095&r2=26698> &r2=26698 Thanks to Josh Mercier for debugging this and getting it fixed in ptlib. Simon