Application: kmail (1.13.2)
KDE Platform Version: 4.4.2 (KDE 4.4.2)
Qt Version: 4.6.2
Operating System: Linux 2.6.33-ARCH x86_64
Distribution (Platform): Archlinux Packages

-- Information about the crash:
1, choose a thread, fold the mails in it
2, tag the thread
3, crash

 -- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[KCrash Handler]
#5  0x00007f184bba88b6 in QString::operator==(QString const&) const () from /usr/lib/libQtCore.so.4
#6  0x00007f184c699353 in KMSetTagCommand::execute() () from /usr/lib/libkmailprivate.so.4
#7  0x00007f184c6947fa in KMCommand::slotPostTransfer(KMCommand::Result) () from /usr/lib/libkmailprivate.so.4
#8  0x00007f184c69e1c3 in KMCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#9  0x00007f184bc6362f in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#10 0x00007f184c68f4ce in KMCommand::messagesTransfered(KMCommand::Result) () from /usr/lib/libkmailprivate.so.4
#11 0x00007f184c6a3dcc in KMCommand::transferSelectedMsgs() () from /usr/lib/libkmailprivate.so.4
#12 0x00007f184c6a3fd8 in KMCommand::slotStart() () from /usr/lib/libkmailprivate.so.4
#13 0x00007f184c69e1a6 in KMCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#14 0x00007f184bc6362f in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#15 0x00007f184bc685ff in ?? () from /usr/lib/libQtCore.so.4
#16 0x00007f184bc60bee in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#17 0x00007f184b049e84 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#18 0x00007f184b04df6a in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#19 0x00007f184d562256 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#20 0x00007f184bc4f79c in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#21 0x00007f184bc7a9b2 in ?? () from /usr/lib/libQtCore.so.4
#22 0x00007f184bc77934 in ?? () from /usr/lib/libQtCore.so.4
#23 0x00007f18423beda2 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#24 0x00007f18423c2c18 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#25 0x00007f18423c2dcc in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#26 0x00007f184bc7800f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#27 0x00007f184b0e94be in ?? () from /usr/lib/libQtGui.so.4
#28 0x00007f184bc4eb82 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#29 0x00007f184bc4edbc in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#30 0x00007f184bc530eb in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#31 0x0000000000403182 in _start ()

Reported using DrKonqi