Application that crashed: krunner
Version of the application: 0.1
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.30-tuxonice-r5 x86_64

What I was doing when the application crashed:
1) I pressed Alt+F2 to bring the dialog.
2) started writing app name (boinc_client)
3) when I entered "boinc" a completion proposal appeared, but I continued entering 
4) proposal disappeared (entered string does not matched the input anymore)
5) eventually all dialog disappeared and the crash handler was shown.

I tried to reproduce the error and all repeated exactly teh same at that time, but now it doesn't.

Hope this help somehow

 -- Backtrace:
Application: Диалог запуска команд (krunner), signal: Aborted
[Current thread is 0 (LWP 10521)]

Thread 5 (Thread 0x7f5c0de4d950 (LWP 11196)):
#0  0x0000003a458d199e in ?? () from /lib/libc.so.6
#1  0x0000003a45875036 in ?? () from /lib/libc.so.6
#2  0x0000003a45871a6b in free () from /lib/libc.so.6
#3  0x0000003215db5460 in ?? () from /usr/lib64/libkdecore.so.5
#4  0x0000003215dd0734 in ?? () from /usr/lib64/libkdecore.so.5
#5  0x0000003215dd10b7 in KLocale::insertCatalog () from /usr/lib64/libkdecore.so.5
#6  0x00007f5c0de69df9 in ?? () from /usr/lib64/libconversion.so.4
#7  0x00007f5c0de59f7c in ?? () from /usr/lib64/libconversion.so.4
#8  0x00007f5c0de55cd4 in Conversion::Converter::Converter () from /usr/lib64/libconversion.so.4
#9  0x00007f5c0de55e06 in ?? () from /usr/lib64/libconversion.so.4
#10 0x00007f5c0de55ed0 in Conversion::Converter::self () from /usr/lib64/libconversion.so.4
#11 0x00007f5c0e0753f5 in ?? () from /usr/lib64/kde4/krunner_converter.so
#12 0x000000321bcbdc86 in Plasma::AbstractRunner::performMatch () from /usr/lib64/libplasma.so.3
#13 0x000000321d20dc32 in ?? () from /usr/lib64/libthreadweaver.so.4
#14 0x000000321d20de55 in ThreadWeaver::Job::execute () from /usr/lib64/libthreadweaver.so.4
#15 0x000000321d20cd9b in ?? () from /usr/lib64/libthreadweaver.so.4
#16 0x000000321d20ceca in ThreadWeaver::Thread::run () from /usr/lib64/libthreadweaver.so.4
#17 0x00000030b005d164 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#18 0x0000003a46406097 in start_thread () from /lib/libpthread.so.0
#19 0x0000003a458c677d in clone () from /lib/libc.so.6
#20 0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7f5c07fff950 (LWP 11197)):
#0  0x0000003a458d199e in ?? () from /lib/libc.so.6
#1  0x0000003a458755a4 in ?? () from /lib/libc.so.6
#2  0x0000003a45874838 in realloc () from /lib/libc.so.6
#3  0x00000030b00a173b in QListData::realloc () from /usr/lib64/qt4/libQtCore.so.4
#4  0x00000030b00a1cb1 in QListData::append () from /usr/lib64/qt4/libQtCore.so.4
#5  0x0000003215d66ab0 in KServiceFactory::serviceOffers () from /usr/lib64/libkdecore.so.5
#6  0x0000003215d7939c in KServiceTypeTrader::defaultOffers () from /usr/lib64/libkdecore.so.5
#7  0x0000003215d795fb in KServiceTypeTrader::query () from /usr/lib64/libkdecore.so.5
#8  0x00007f5c105b43e7 in ?? () from /usr/lib64/kde4/krunner_services.so
#9  0x000000321bcbdc86 in Plasma::AbstractRunner::performMatch () from /usr/lib64/libplasma.so.3
#10 0x000000321d20dc32 in ?? () from /usr/lib64/libthreadweaver.so.4
#11 0x000000321d20de55 in ThreadWeaver::Job::execute () from /usr/lib64/libthreadweaver.so.4
#12 0x000000321d20cd9b in ?? () from /usr/lib64/libthreadweaver.so.4
#13 0x000000321d20ceca in ThreadWeaver::Thread::run () from /usr/lib64/libthreadweaver.so.4
#14 0x00000030b005d164 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#15 0x0000003a46406097 in start_thread () from /lib/libpthread.so.0
#16 0x0000003a458c677d in clone () from /lib/libc.so.6
#17 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7f5c0d64c950 (LWP 11198)):
[KCrash Handler]
#5  0x0000003a45831205 in raise () from /lib/libc.so.6
#6  0x0000003a4583257e in abort () from /lib/libc.so.6
#7  0x0000003a4586ade7 in ?? () from /lib/libc.so.6
#8  0x0000003a458700bd in ?? () from /lib/libc.so.6
#9  0x0000003a45871a76 in free () from /lib/libc.so.6
#10 0x00000030b005f102 in QByteArray::operator= () from /usr/lib64/qt4/libQtCore.so.4
#11 0x0000003215db5397 in ?? () from /usr/lib64/libkdecore.so.5
#12 0x0000003215db64d6 in ?? () from /usr/lib64/libkdecore.so.5
#13 0x0000003215dcd567 in ?? () from /usr/lib64/libkdecore.so.5
#14 0x0000003215dce4d9 in KLocale::translateRaw () from /usr/lib64/libkdecore.so.5
#15 0x0000003215ddfe63 in ?? () from /usr/lib64/libkdecore.so.5
#16 0x0000003215de11d7 in KLocalizedString::toString () from /usr/lib64/libkdecore.so.5
#17 0x00007f5c0eaab184 in ?? () from /usr/lib64/kde4/krunner_sessions.so
#18 0x00007f5c0eaa94b3 in ?? () from /usr/lib64/kde4/krunner_sessions.so
#19 0x000000321bcbdc86 in Plasma::AbstractRunner::performMatch () from /usr/lib64/libplasma.so.3
#20 0x000000321d20dc32 in ?? () from /usr/lib64/libthreadweaver.so.4
#21 0x000000321d20de55 in ThreadWeaver::Job::execute () from /usr/lib64/libthreadweaver.so.4
#22 0x000000321d20cd9b in ?? () from /usr/lib64/libthreadweaver.so.4
#23 0x000000321d20ceca in ThreadWeaver::Thread::run () from /usr/lib64/libthreadweaver.so.4
#24 0x00000030b005d164 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#25 0x0000003a46406097 in start_thread () from /lib/libpthread.so.0
#26 0x0000003a458c677d in clone () from /lib/libc.so.6
#27 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f5c0ce4b950 (LWP 11199)):
#0  0x0000003a4640aa09 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00000030b005dcbd in QWaitCondition::wait () from /usr/lib64/qt4/libQtCore.so.4
#2  0x000000321d20bf48 in ?? () from /usr/lib64/libthreadweaver.so.4
#3  0x000000321d20e7d0 in ?? () from /usr/lib64/libthreadweaver.so.4
#4  0x000000321d20ce04 in ?? () from /usr/lib64/libthreadweaver.so.4
#5  0x000000321d20ceca in ThreadWeaver::Thread::run () from /usr/lib64/libthreadweaver.so.4
#6  0x00000030b005d164 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#7  0x0000003a46406097 in start_thread () from /lib/libpthread.so.0
#8  0x0000003a458c677d in clone () from /lib/libc.so.6
#9  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f5c223a27b0 (LWP 10521)):
#0  0x0000003a458d199e in ?? () from /lib/libc.so.6
#1  0x0000003a45875036 in ?? () from /lib/libc.so.6
#2  0x0000003a45871a6b in free () from /lib/libc.so.6
#3  0x000000321bd50b47 in Plasma::RunnerManager::qt_metacall () from /usr/lib64/libplasma.so.3
#4  0x00000030b018ec07 in QMetaObject::activate () from /usr/lib64/qt4/libQtCore.so.4
#5  0x000000321d20d462 in ThreadWeaver::Job::done () from /usr/lib64/libthreadweaver.so.4
#6  0x000000321d20d522 in ThreadWeaver::Job::qt_metacall () from /usr/lib64/libthreadweaver.so.4
#7  0x00000030b018bc24 in QObject::event () from /usr/lib64/qt4/libQtCore.so.4
#8  0x0000003cadf9fe4e in QApplicationPrivate::notify_helper () from /usr/lib64/qt4/libQtGui.so.4
#9  0x0000003cadfa0ade in QApplication::notify () from /usr/lib64/qt4/libQtGui.so.4
#10 0x000000321643013b in KApplication::notify () from /usr/lib64/libkdeui.so.5
#11 0x00000030b017a463 in QCoreApplication::notifyInternal () from /usr/lib64/qt4/libQtCore.so.4
#12 0x00000030b017b462 in QCoreApplicationPrivate::sendPostedEvents () from /usr/lib64/qt4/libQtCore.so.4
#13 0x00000030b01a6b53 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#14 0x0000003a49a3ecc2 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#15 0x0000003a49a3f505 in ?? () from /usr/lib/libglib-2.0.so.0
#16 0x0000003a49a3fa0b in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#17 0x00000030b01a6e1e in QEventDispatcherGlib::processEvents () from /usr/lib64/qt4/libQtCore.so.4
#18 0x0000003cae02e08f in ?? () from /usr/lib64/qt4/libQtGui.so.4
#19 0x00000030b0179a15 in QEventLoop::processEvents () from /usr/lib64/qt4/libQtCore.so.4
#20 0x00000030b0179c79 in QEventLoop::exec () from /usr/lib64/qt4/libQtCore.so.4
#21 0x00000030b017b7a9 in QCoreApplication::exec () from /usr/lib64/qt4/libQtCore.so.4
#22 0x000000321c2277d9 in kdemain () from /usr/lib64/libkdeinit4_krunner.so
#23 0x0000003a4581e5e4 in __libc_start_main () from /lib/libc.so.6
#24 0x0000000000400909 in _start ()

Reported using DrKonqi