Here is the code:
[Thread debugging using libthread_db enabled]
[New Thread -1231751504 (LWP 4689)]
(no debugging symbols found)
(no debugging symbols found)
[KCrash handler]
#6 0xffffe410 in __kernel_vsyscall ()
#7 0xb6cf8781 in raise () from /lib/libc.so.6
#8 0xb6cf9e79 in abort () from /lib/libc.so.6
#9 0xb6ecc084 in __gnu_cxx::__verbose_terminate_handler ()
from /usr/lib/libstdc++.so.6
#10 0xb6ec9a75 in std::set_unexpected () from /usr/lib/libstdc++.so.6
#11 0xb6ec9ab2 in std::terminate () from /usr/lib/libstdc++.so.6
#12 0xb6ec9b6a in __cxa_rethrow () from /usr/lib/libstdc++.so.6
#13 0xb7ef3a59 in bt::MultiFileCache::downloadStatusChanged ()
from /opt/kde3/lib/libktorrent.so.0
#14 0xb7ee1aeb in bt::ChunkManager::downloadStatusChanged ()
from /opt/kde3/lib/libktorrent.so.0
#15 0xb7ee1d54 in bt::ChunkManager::qt_invoke ()
from /opt/kde3/lib/libktorrent.so.0
#16 0xb716a519 in QObject::activate_signal ()
from /usr/lib/qt3/lib/libqt-mt.so.3
#17 0xb7ed34c8 in bt::TorrentFile::downloadStatusChanged ()
from /opt/kde3/lib/libktorrent.so.0
#18 0xb7ed35e7 in bt::TorrentFile::setDoNotDownload ()
from /opt/kde3/lib/libktorrent.so.0
#19 0xb7ee1f2d in bt::ChunkManager::loadFileInfo ()
from /opt/kde3/lib/libktorrent.so.0
#20 0xb7ee4242 in bt::ChunkManager::loadIndexFile ()
from /opt/kde3/lib/libktorrent.so.0
#21 0xb7efd57a in bt::TorrentControl::init ()
from /opt/kde3/lib/libktorrent.so.0
#22 0x08079567 in ?? ()
#23 0x080753c9 in ?? ()
#24 0x08079dfd in ?? ()
#25 0x0807a484 in ?? ()
#26 0xb77ae99a in KUniqueApplication::processDelayed ()
from /opt/kde3/lib/libkdecore.so.4
#27 0xb77b1f68 in KUniqueApplication::qt_invoke ()
from /opt/kde3/lib/libkdecore.so.4
#28 0x0805cc3f in ?? ()
#29 0xb716a519 in QObject::activate_signal ()
from /usr/lib/qt3/lib/libqt-mt.so.3
#30 0xb74a9b8e in QSignal::signal () from /usr/lib/qt3/lib/libqt-mt.so.3
#31 0xb71862d5 in QSignal::activate () from /usr/lib/qt3/lib/libqt-mt.so.3
#32 0xb718d7d3 in QSingleShotTimer::event ()
from /usr/lib/qt3/lib/libqt-mt.so.3
#33 0xb710aa37 in QApplication::internalNotify ()
from /usr/lib/qt3/lib/libqt-mt.so.3
#34 0xb710b731 in QApplication::notify () from /usr/lib/qt3/lib/libqt-mt.so.3
#35 0xb77caa6e in KApplication::notify () from /opt/kde3/lib/libkdecore.so.4
#36 0xb70ffa3f in QEventLoop::activateTimers ()
from /usr/lib/qt3/lib/libqt-mt.so.3
#37 0xb70b995c in QEventLoop::processEvents ()
from /usr/lib/qt3/lib/libqt-mt.so.3
#38 0xb7121911 in QEventLoop::enterLoop () from /usr/lib/qt3/lib/libqt-mt.so.3
#39 0xb712178e in QEventLoop::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#40 0xb710a4cf in QApplication::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#41 0x0807508a in ?? ()
#42 0xb6ce5808 in __libc_start_main () from /lib/libc.so.6
#43 0x0805b1f1 in ?? ()

It looks the same as this bug report :

http://bugs.kde.org/show_bug.cgi?id=120932

Can you give some more info, so I can reproduce this.

This happens at start-up, so did anything unusual occurred the session before this crash ?