Application that crashed: kmail
Version of the application: 1.12.4
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.5.3
Operating System: Linux 2.6.31-ARCH x86_64

What I was doing when the application crashed:
I was in the inbox, teaching kmail what is ham or spam on my new account.

I clicked on the first message, clicked the "ham" button in the toolbar, kmail moves to the next message, I click on "ham", etc.

 -- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fb0db5d1760 (LWP 9162))]

Thread 2 (Thread 0x7fb0c3c40710 (LWP 9202)):
#0  0x00007fb0d7fa807c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fb0d9885c6b in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#2  0x00007fb0d76a5c9c in ?? () from /usr/lib/libQtNetwork.so.4
#3  0x00007fb0d9884ba5 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007fb0d7fa381a in start_thread () from /lib/libpthread.so.0
#5  0x00007fb0d84ddc7d in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fb0db5d1760 (LWP 9162)):
[KCrash Handler]
#5  0x00007fb0da16d26c in KMFolder::folderType() const () from /usr/lib/libkmailprivate.so.4
#6  0x00007fb0da3887fd in KMail::ImapJob::slotProcessedSize(KJob*, unsigned long long) () from /usr/lib/libkmailprivate.so.4
#7  0x00007fb0da38d8d2 in KMail::ImapJob::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#8  0x00007fb0d997ed3c in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#9  0x00007fb0daa509cb in KJob::processedSize(KJob*, unsigned long long) () from /usr/lib/libkdecore.so.5
#10 0x00007fb0daa51e22 in KJob::setProcessedAmount(KJob::Unit, unsigned long long) () from /usr/lib/libkdecore.so.5
#11 0x00007fb0d3930bef in KIO::TransferJob::sendAsyncData(QByteArray const&) () from /usr/lib/libkio.so.5
#12 0x00007fb0d3932761 in KIO::TransferJob::slotDataReq() () from /usr/lib/libkio.so.5
#13 0x00007fb0d3935a51 in KIO::TransferJob::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkio.so.5
#14 0x00007fb0d997ed3c in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#15 0x00007fb0d39f798d in KIO::SlaveInterface::dispatch(int, QByteArray const&) () from /usr/lib/libkio.so.5
#16 0x00007fb0d39f4123 in KIO::SlaveInterface::dispatch() () from /usr/lib/libkio.so.5
#17 0x00007fb0d39e6f4d in KIO::Slave::gotInput() () from /usr/lib/libkio.so.5
#18 0x00007fb0d39e906c in KIO::Slave::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkio.so.5
#19 0x00007fb0d997ed3c in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#20 0x00007fb0d3903d97 in KIO::ConnectionPrivate::dequeue() () from /usr/lib/libkio.so.5
#21 0x00007fb0d3903ebd in KIO::Connection::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkio.so.5
#22 0x00007fb0d9979059 in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#23 0x00007fb0d8e1b07c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#24 0x00007fb0d8e2234e in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#25 0x00007fb0db00b8f6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#26 0x00007fb0d9969bfc in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#27 0x00007fb0d996a80a in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQtCore.so.4
#28 0x00007fb0d9992583 in ?? () from /usr/lib/libQtCore.so.4
#29 0x00007fb0d152826e in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#30 0x00007fb0d152bc28 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#31 0x00007fb0d152bd50 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#32 0x00007fb0d9992123 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#33 0x00007fb0d8eae14e in ?? () from /usr/lib/libQtGui.so.4
#34 0x00007fb0d9968532 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#35 0x00007fb0d9968904 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#36 0x00007fb0d996aab9 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#37 0x0000000000402f89 in _start ()

Reported using DrKonqi