Version:            (using KDE KDE 3.5.5)
Installed from:    Ubuntu Packages

This is the first time that I could obtain a backtrace with the occasionally happening index corruption.

Symptoms: After starting kontact/kmail some recent entries get corrupted as soon as I click on them. No mesage body is shown
and the problem continues with more messages clicked. A "repair index" operation does not help.

This time I got a crash shortly afterwards:

System configuration startup check disabled.

Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread -1249143120 (LWP 5403)]
[New Thread -1276597344 (LWP 5791)]
[New Thread -1268204640 (LWP 5790)]
[New Thread -1259811936 (LWP 5789)]
[New Thread -1251419232 (LWP 5788)]
[KCrash handler]
#6  KMHeaders::writeSortOrder (this=0x8886c80)
    at /build/buildd/kdepim-3.5.5/./kmail/kmheaders.cpp:2593
#7  0xb7c40f5a in ~KMHeaders (this=0x8886c80)
    at /build/buildd/kdepim-3.5.5/./kmail/kmheaders.cpp:214
#8  0xb7dc72dc in KMMainWidget::destruct (this=0x88739f0)
    at /build/buildd/kdepim-3.5.5/./kmail/kmmainwidget.cpp:235
#9  0xb7dc9f10 in ~KMMainWidget (this=0x88739f0)
    at /build/buildd/kdepim-3.5.5/./kmail/kmmainwidget.cpp:221
#10 0xb70fbb1b in QWidget::~QWidget () from /usr/lib/libqt-mt.so.3
#11 0xb71ccc6c in QMainWindow::~QMainWindow () from /usr/lib/libqt-mt.so.3
#12 0xb5f1f7d6 in ~KMainWindow (this=0x8865e18, __vtt_parm=0xb7f186ac)
    at /build/buildd/kdelibs-3.5.5/./kdeui/kmainwindow.cpp:322
#13 0xb7bc2a66 in ~KMMainWin (this=0x8865e18)
    at /build/buildd/kdepim-3.5.5/./kmail/kmmainwin.cpp:110
#14 0xb70be020 in QObject::event () from /usr/lib/libqt-mt.so.3
#15 0xb70f565b in QWidget::event () from /usr/lib/libqt-mt.so.3
#16 0xb71cbc5e in QMainWindow::event () from /usr/lib/libqt-mt.so.3
#17 0xb7055b88 in QApplication::internalNotify () from /usr/lib/libqt-mt.so.3
#18 0xb7058552 in QApplication::notify () from /usr/lib/libqt-mt.so.3
#19 0xb777edb2 in KApplication::notify (this=0xbf9cf2e4, receiver=0x8865e18, 
    event=0x870f0a0)
    at /build/buildd/kdelibs-3.5.5/./kdecore/kapplication.cpp:550
#20 0xb6fe8389 in QApplication::sendEvent () from /usr/lib/libqt-mt.so.3
#21 0xb7056bc0 in QApplication::sendPostedEvents ()
   from /usr/lib/libqt-mt.so.3
#22 0xb7056cc8 in QApplication::sendPostedEvents ()
   from /usr/lib/libqt-mt.so.3
#23 0xb6ffc391 in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#24 0xb707025e in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#25 0xb707006e in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#26 0xb7057731 in QApplication::exec () from /usr/lib/libqt-mt.so.3
#27 0x0804a0fe in main (argc=)
    at /build/buildd/kdepim-3.5.5/./kmail/main.cpp:110
#28 0xb781c8cc in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#29 0x08049e61 in _start ()