Application that crashed: kontact
Version of the application: 4.3.2
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.3
Operating System: Linux 2.6.31-ARCH x86_64
Distribution: "(none)"

What I was doing when the application crashed:
KDE installed from the repos of Arch. Sometimes when I move a bulk of emails to a folder, I get a crash. 

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f64d998b750 (LWP 31469))]

Thread 2 (Thread 0x7f64b9a5e910 (LWP 31841)):
#0  0x00007f64d34fcdd9 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007f64d81bcc6b in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#2  0x00007f64d266ac9c in ?? () from /usr/lib/libQtNetwork.so.4
#3  0x00007f64d81bbba5 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007f64d34f857a in start_thread () from /lib/libpthread.so.0
#5  0x00007f64d702d14d in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f64d998b750 (LWP 31469)):
[KCrash Handler]
#5  0x00007f64c28138e0 in KMail::FolderJob::msgList() const () from /usr/lib/libkmailprivate.so.4
#6  0x00007f64c26bd3b3 in KMAcctImap::ignoreJobsForMessage(KMMessage*) () from /usr/lib/libkmailprivate.so.4
#7  0x00007f64c27d6287 in KMMoveCommand::execute() () from /usr/lib/libkmailprivate.so.4
#8  0x00007f64c27bbe6a in KMCommand::slotPostTransfer(KMCommand::Result) () from /usr/lib/libkmailprivate.so.4
#9  0x00007f64c27c6023 in KMCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#10 0x00007f64c27d7370 in KMMoveCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#11 0x00007f64d82b5d3c in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#12 0x00007f64c27b8fee in KMCommand::messagesTransfered(KMCommand::Result) () from /usr/lib/libkmailprivate.so.4
#13 0x00007f64c27d41a8 in KMCommand::transferSelectedMsgs() () from /usr/lib/libkmailprivate.so.4
#14 0x00007f64c27d43cf in KMCommand::slotStart() () from /usr/lib/libkmailprivate.so.4
#15 0x00007f64c27c6006 in KMCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#16 0x00007f64c27d7370 in KMMoveCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#17 0x00007f64d82b5d3c in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#18 0x00007f64d82bad7f in ?? () from /usr/lib/libQtCore.so.4
#19 0x00007f64d82afce3 in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#20 0x00007f64d775207c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#21 0x00007f64d775934e in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#22 0x00007f64d8c41586 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#23 0x00007f64d82a0bfc in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#24 0x00007f64d82cc3e2 in ?? () from /usr/lib/libQtCore.so.4
#25 0x00007f64d82c93f8 in ?? () from /usr/lib/libQtCore.so.4
#26 0x00007f64d0e6f1fe in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#27 0x00007f64d0e72bb8 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#28 0x00007f64d0e72ce0 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#29 0x00007f64d82c9123 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#30 0x00007f64d77e514e in ?? () from /usr/lib/libQtGui.so.4
#31 0x00007f64d829f532 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#32 0x00007f64d829f904 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#33 0x00007f64d82a1ab9 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#34 0x0000000000403ef7 in _start ()

Reported using DrKonqi