Version:           1.11.0 (kde4.2 branch) (using Devel)
Installed from:    Compiled sources

What I did:
1. There was an IMAP auth error (sorry, don't remember what one)
2. after clicking it away, the password dialog appeared
3. I cancelled it
4. then I fetched all mailboxes again
After a few seconds, KMail crashed with the following backtrace.
It is not reproducable for me since I do not know how to receive this auth error.

Anwendung: KMail (kmail), Signal SIGABRT

Thread 1 (Thread 0xb3bed6f0 (LWP 2436)):
[KCrash Handler]
#6  0xb7fd9424 in __kernel_vsyscall ()
#7  0xb5d72640 in raise () from /lib/i686/cmov/libc.so.6
#8  0xb5d74018 in abort () from /lib/i686/cmov/libc.so.6
#9  0xb6a6c6cd in qt_message_output () from /usr/lib/libQtCore.so.4
#10 0xb6a6c796 in qFatal () from /usr/lib/libQtCore.so.4
#11 0xb6a6c825 in qt_assert () from /usr/lib/libQtCore.so.4
#12 0xb754ce7c in KMail::ImapAccountBase::makeConnection (this=0x8386ad8) at /home/compiler/kde/src/KDE/kdepim/kmail/imapaccountbase.cpp:304
#13 0xb7555d4a in KMAcctImap::makeConnection (this=0x8386ad8) at /home/compiler/kde/src/KDE/kdepim/kmail/kmacctimap.cpp:562
#14 0xb75571e2 in KMAcctImap::processNewMail (this=0x8386ad8, interactive=true) at /home/compiler/kde/src/KDE/kdepim/kmail/kmacctimap.cpp:278
#15 0xb74d9a01 in KMail::AccountManager::processNextCheck (this=0x80c6eb8, _newMail=false) at /home/compiler/kde/src/KDE/kdepim/kmail/accountmanager.cpp:221
#16 0xb74d9e34 in KMail::AccountManager::qt_metacall (this=0x80c6eb8, _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbfef2418) at /home/compiler/kde/build/KDE/kdepim/kmail/accountmanager.moc:95
#17 0xb6b78be0 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#18 0xb6b79962 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#19 0xb7444591 in KMAccount::finishedCheck (this=0x8386ad8, _t1=false, _t2=KMAccount::CheckOK) at /home/compiler/kde/build/KDE/kdepim/kmail/kmaccount.moc:158
#20 0xb7444648 in KMAccount::checkDone (this=0x8386ad8, newmail=false, status=KMAccount::CheckOK) at /home/compiler/kde/src/KDE/kdepim/kmail/kmaccount.cpp:511
#21 0xb7558647 in KMAcctImap::killAllJobs (this=0x8386ad8, disconnectSlave=true) at /home/compiler/kde/src/KDE/kdepim/kmail/kmacctimap.cpp:198
#22 0xb75481d2 in KMail::ImapAccountBase::handleError (this=0x8386ad8, errorCode=146, errorMsg=@0xbfef294c, job=0x0, context=@0xbfef2638, abortSync=true)
    at /home/compiler/kde/src/KDE/kdepim/kmail/imapaccountbase.cpp:1015
#23 0xb7558766 in KMAcctImap::handleError (this=0x8386ad8, errorCode=146, errorMsg=@0xbfef294c, job=0x0, context=@0xbfef2638, abortSync=true)
    at /home/compiler/kde/src/KDE/kdepim/kmail/kmacctimap.cpp:131
#24 0xb754e8bb in KMail::ImapAccountBase::slotSchedulerSlaveError (this=0x8386ad8, aSlave=0x8c3dc80, errorCode=146, errorMsg=@0xbfef294c)
    at /home/compiler/kde/src/KDE/kdepim/kmail/imapaccountbase.cpp:630
#25 0xb754ec05 in KMail::ImapAccountBase::qt_metacall (this=0x8386ad8, _c=QMetaObject::InvokeMetaMethod, _id=12, _a=0xbfef2754) at /home/compiler/kde/build/KDE/kdepim/kmail/imapaccountbase.moc:129
#26 0xb755707c in KMAcctImap::qt_metacall (this=0x8386ad8, _c=QMetaObject::InvokeMetaMethod, _id=22, _a=0xbfef2754) at /home/compiler/kde/build/KDE/kdepim/kmail/kmacctimap.moc:76
#27 0xb6b78be0 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#28 0xb6b79962 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#29 0xb6e762b4 in KIO::Scheduler::slaveError (this=0x8387310, _t1=0x8c3dc80, _t2=146, _t3=@0xbfef294c) at /home/compiler/kde/build/KDE/kdelibs/kio/scheduler.moc:124
#30 0xb6e76e66 in KIO::SchedulerPrivate::slotSlaveError (this=0x8341188, errorNr=146, errorMsg=@0xbfef294c) at /home/compiler/kde/src/KDE/kdelibs/kio/kio/scheduler.cpp:928
#31 0xb6e7a230 in KIO::Scheduler::qt_metacall (this=0x8387310, _c=QMetaObject::InvokeMetaMethod, _id=9, _a=0xbfef2898) at /home/compiler/kde/build/KDE/kdelibs/kio/scheduler.moc:104
#32 0xb6b78be0 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#33 0xb6b79962 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#34 0xb6e8b12d in KIO::SlaveInterface::error (this=0x8c3dc80, _t1=146, _t2=@0xbfef294c) at /home/compiler/kde/build/KDE/kdelibs/kio/slaveinterface.moc:151
#35 0xb6e8d106 in KIO::SlaveInterface::dispatch (this=0x8c3dc80, _cmd=102, rawdata=@0xbfef2a04) at /home/compiler/kde/src/KDE/kdelibs/kio/kio/slaveinterface.cpp:208
#36 0xb6e8cd7a in KIO::SlaveInterface::dispatch (this=0x8c3dc80) at /home/compiler/kde/src/KDE/kdelibs/kio/kio/slaveinterface.cpp:91
#37 0xb6e7f528 in KIO::Slave::gotInput (this=0x8c3dc80) at /home/compiler/kde/src/KDE/kdelibs/kio/kio/slave.cpp:322
#38 0xb6e80998 in KIO::Slave::qt_metacall (this=0x8c3dc80, _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfef2b08) at /home/compiler/kde/build/KDE/kdelibs/kio/slave.moc:75
#39 0xb6b78be0 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#40 0xb6b79962 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#41 0xb6da7dcb in KIO::Connection::readyRead (this=0x8c3fe98) at /home/compiler/kde/build/KDE/kdelibs/kio/connection.moc:84
#42 0xb6da8d07 in KIO::ConnectionPrivate::dequeue (this=0x8c40060) at /home/compiler/kde/src/KDE/kdelibs/kio/kio/connection.cpp:82
#43 0xb6da9c41 in KIO::Connection::qt_metacall (this=0x8c3fe98, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0x8ec76f0) at /home/compiler/kde/build/KDE/kdelibs/kio/connection.moc:72
#44 0xb6b71d7b in QMetaCallEvent::placeMetaCall () from /usr/lib/libQtCore.so.4
#45 0xb6b738f1 in QObject::event () from /usr/lib/libQtCore.so.4
#46 0xb60fd79c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#47 0xb610561e in QApplication::notify () from /usr/lib/libQtGui.so.4
#48 0xb7e2a093 in KApplication::notify (this=0xbfef33e8, receiver=0x8c3fe98, event=0x9098a40) at /home/compiler/kde/src/KDE/kdelibs/kdeui/kernel/kapplication.cpp:307
#49 0xb6b640e1 in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#50 0xb6b64d65 in QCoreApplicationPrivate::sendPostedEvents () from /usr/lib/libQtCore.so.4
#51 0xb6b64f5d in QCoreApplication::sendPostedEvents () from /usr/lib/libQtCore.so.4
#52 0xb6197e6f in ?? () from /usr/lib/libQtGui.so.4
#53 0xb6b627aa in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#54 0xb6b6296a in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#55 0xb6b65025 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#56 0xb60fd617 in QApplication::exec () from /usr/lib/libQtGui.so.4
#57 0x0804b519 in main (argc=3, argv=0xbfef34c4) at /home/compiler/kde/src/KDE/kdepim/kmail/main.cpp:146