Application that crashed: kmail
Version of the application: 1.12.4
KDE Version: 4.3.5 (KDE 4.3.5)
Qt Version: 4.6.2
Operating System: Linux 2.6.31-gentoo-r10-04 x86_64

What I was doing when the application crashed:
I was writing a mail, then switched to a folder view within the main window to grab some mails and attach them to the mail I was writing, but kmail crashed before I even could select the folder.  Internet connection to IMAP accounts was on all the time, but I am not aware if kmail was checking any of them at the moment.
    I have done this operation a dozen times without kmail crashing.

 -- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[KCrash Handler]
#5  0x00000000022da0c0 in ?? ()
#6  0x00007f38a1ee5381 in KMReaderWin::parseMsg (this=0xcb4020, aMsg=0x42866e0) at /var/tmp/portage/kde-base/kmail-4.3.5/work/kmail-4.3.5/kmail/kmreaderwin.cpp:1691
#7  0x00007f38a1ed3654 in KMReaderWin::displayMessage (this=0xcb4020) at /var/tmp/portage/kde-base/kmail-4.3.5/work/kmail-4.3.5/kmail/kmreaderwin.cpp:1608
#8  0x00007f38a1ed3915 in KMReaderWin::updateReaderWin (this=0xcb4020) at /var/tmp/portage/kde-base/kmail-4.3.5/work/kmail-4.3.5/kmail/kmreaderwin.cpp:1548
#9  0x00007f38a1ee122d in KMReaderWin::qt_metacall (this=0xcb4020, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff5f2daa40)
    at /var/tmp/portage/kde-base/kmail-4.3.5/work/kmail-4.3.5_build/kmail/kmreaderwin.moc:174
#10 0x00007f389ddf4197 in QMetaObject::activate (sender=0xcb40c8, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x1) at kernel/qobject.cpp:3285
#11 0x00007f389ddf8843 in QObject::event (this=0xcb40c8, e=0x651094) at kernel/qobject.cpp:1204
#12 0x00007f389c91c64d in QApplicationPrivate::notify_helper (this=0x7912b0, receiver=0xcb40c8, e=0x7fff5f2db250) at kernel/qapplication.cpp:4300
#13 0x00007f389c91f444 in QApplication::notify (this=0x7fff5f2db6b0, receiver=0xcb40c8, e=0x7fff5f2db250) at kernel/qapplication.cpp:3704
#14 0x00007f38a2dfc92b in KApplication::notify (this=0x7fff5f2db6b0, receiver=0xcb40c8, event=0x7fff5f2db250)
    at /var/tmp/portage/kde-base/kdelibs-4.3.5/work/kdelibs-4.3.5/kdeui/kernel/kapplication.cpp:302
#15 0x00007f389dddfd8b in QCoreApplication::notifyInternal (this=0x7fff5f2db6b0, receiver=0xcb40c8, event=0x7fff5f2db250) at kernel/qcoreapplication.cpp:704
#16 0x00007f389de12187 in QCoreApplication::sendEvent (this=0x794b50) at kernel/qcoreapplication.h:215
#17 QTimerInfoList::activateTimers (this=0x794b50) at kernel/qeventdispatcher_unix.cpp:603
#18 0x00007f389de0eec4 in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:184
#19 0x00007f3895d6d06d in g_main_dispatch (context=0x7939f0) at gmain.c:1960
#20 0x00007f3895d6ee45 in IA__g_main_context_dispatch (context=0x7939f0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2513
#21 g_main_context_iterate (context=0x7939f0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2591
#22 0x00007f3895d6ef8c in IA__g_main_context_iteration (context=0x7939f0, may_block=1) at gmain.c:2654
#23 0x00007f389de0ec1c in QEventDispatcherGlib::processEvents (this=0x60b250, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:412
#24 0x00007f389c9df29f in QGuiEventDispatcherGlib::processEvents (this=0x42866e0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#25 0x00007f389ddde9b2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#26 0x00007f389ddded84 in QEventLoop::exec (this=0x7fff5f2db500, flags=...) at kernel/qeventloop.cpp:201
#27 0x00007f389dde12b6 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#28 0x0000000000403501 in main (argc=<value optimized out>, argv=<value optimized out>) at /var/tmp/portage/kde-base/kmail-4.3.5/work/kmail-4.3.5/kmail/main.cpp:146

Reported using DrKonqi