The is KDE2 kmail running on rc1.

kmail seem to run fine and terminates normally if the file-exit or
file-close menu items are selected.  However, if the window's exit ("X")
button is used to close/terminate, then kmail crashes.

The traceback I got is:

Here is a backtrace generated by DrKonqi:
(no debugging symbols found)...(no debugging symbols found)...
(no debugging symbols found)...(no debugging symbols found)...
(no debugging symbols found)...(no debugging symbols found)...
[New Thread 1024 (LWP 1082)]
0x4131bed9 in __wait4 () from /lib/libc.so.6
#0  0x4131bed9 in __wait4 () from /lib/libc.so.6
#1  0x41383668 in __DTOR_END__ () from /lib/libc.so.6
#2  0x40a2ac67 in KCrash::defaultCrashHandler ()
   from /usr/lib/kde2/lib/libkdecore.so.3
#3  <signal handler called>
#4  0x40edc3cc in QToolBar::~QToolBar () from
/usr/lib/qt-2.2.0/lib/libqt.so.2
#5  0x40701287 in KToolBar::~KToolBar () from
/usr/lib/kde2/lib/libkdeui.so.3
#6  0x40dfcf8c in QWidget::~QWidget () from
/usr/lib/qt-2.2.0/lib/libqt.so.2
#7  0x40e79a87 in QMainWindow::~QMainWindow ()
   from /usr/lib/qt-2.2.0/lib/libqt.so.2
#8  0x4074b6a7 in KMainWindow::~KMainWindow ()
   from /usr/lib/kde2/lib/libkdeui.so.3
#9  0x4075130c in KTMainWindow::~KTMainWindow ()
   from /usr/lib/kde2/lib/libkdeui.so.3
#10 0x813a4e8 in KDialog::marginHint ()
#11 0x807d8ee in KDialog::marginHint ()
#12 0x40e0135a in QWidget::close () from /usr/lib/qt-2.2.0/lib/libqt.so.2
#13 0x40cbb728 in QETWidget::translateCloseEvent ()
   from /usr/lib/qt-2.2.0/lib/libqt.so.2
#14 0x40cb5ec8 in QApplication::x11ClientMessage ()
   from /usr/lib/qt-2.2.0/lib/libqt.so.2
#15 0x40cb6d84 in QApplication::x11ProcessEvent ()
   from /usr/lib/qt-2.2.0/lib/libqt.so.2
#16 0x40cb5bb7 in QApplication::processNextEvent ()
   from /usr/lib/qt-2.2.0/lib/libqt.so.2
#17 0x40d34afc in QApplication::enter_loop ()
   from /usr/lib/qt-2.2.0/lib/libqt.so.2
#18 0x40cb5b37 in QApplication::exec () from
/usr/lib/qt-2.2.0/lib/libqt.so.2
#19 0x817bbcf in KDialog::marginHint ()
#20 0x41283665 in __libc_start_main (
    main=0x817bab0 <KDialog::marginHint(void)+1135544>, argc=5, 
    ubp_av=0xbffff974, init=0x80607d8 <_init>, fini=0x81b0448 <_fini>, 
    rtld_fini=0x4000dca4 <_dl_fini>, stack_end=0xbffff96c)
    at ../sysdeps/generic/libc-start.c:111