Application: systemsettings (4.11.8)
KDE Platform Version: 4.12.4
Qt Version: 4.8.6
Operating System: Linux 3.14-1-686-pae i686
Distribution: Debian GNU/Linux unstable (sid)

-- Information about the crash:
- What I was doing when the application crashed:

1) System Settings -> Display and monitor
2) Second screen attached to laptop get disconnected, dialog prompted with one monitor ( laptop) only
3) reconnected cable -> crash

The crash can be reproduced sometimes.

-- Backtrace:
Application: System Settings (systemsettings), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/i686/cmov/libthread_db.so.1".
[Current thread is 1 (Thread 0xb1e12800 (LWP 14473))]

Thread 2 (Thread 0xae2beb40 (LWP 14475)):
#0  0xb7710424 in __kernel_vsyscall ()
#1  0xb3330c5b in pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:187
#2  0xb5cfce2c in __pthread_cond_wait (cond=0xb45438d0, mutex=0xb45438b8) at forward.c:149
#3  0xb44414f2 in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#4  0xb444153f in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#5  0xb332ced9 in start_thread (arg=0xae2beb40) at pthread_create.c:312
#6  0xb5cf02ae in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

Thread 1 (Thread 0xb1e12800 (LWP 14473)):
[KCrash Handler]
#7  0xae2c9094 in KScreen::Output::id() const () from /usr/lib/i386-linux-gnu/libkscreen.so.1
#8  0xae2f9757 in ?? () from /usr/lib/i386-linux-gnu/kde4/plugins/kscreen/1/KSC_XRandR.so
#9  0xae2f5ded in ?? () from /usr/lib/i386-linux-gnu/kde4/plugins/kscreen/1/KSC_XRandR.so
#10 0xae2c6109 in KScreen::Config::current() () from /usr/lib/i386-linux-gnu/libkscreen.so.1
#11 0xae3165fe in ?? () from /usr/lib/kde4/kcm_kscreen.so
#12 0xb73d0621 in KCModuleProxy::load (this=this@entry=0x8cbf340) at ../../kutils/kcmoduleproxy.cpp:270
#13 0xb73ad006 in ModuleView::resolveChanges (this=0x8b62900, currentProxy=0x8cbf340) at ../../../systemsettings/core/ModuleView.cpp:250
#14 0xb73ad06e in ModuleView::resolveChanges (this=0x8b62900) at ../../../systemsettings/core/ModuleView.cpp:224
#15 0xaef9cae2 in IconMode::backToOverview (this=0x8b61570) at ../../../systemsettings/icons/IconMode.cpp:157
#16 0xb6032cd5 in QMetaObject::activate (sender=sender@entry=0x8b61ad8, m=m@entry=0xb6f56ad8 <QAction::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0xbfa978c8) at kernel/qobject.cpp:3567
#17 0xb65fd63d in QAction::triggered (this=this@entry=0x8b61ad8, _t1=false) at .moc/release-shared/moc_qaction.cpp:276
#18 0xb65ff234 in QAction::activate (this=0x8b61ad8, event=event@entry=QAction::Trigger) at kernel/qaction.cpp:1257
#19 0xb6aed200 in trigger (this=<optimized out>) at ../../include/QtGui/../../src/gui/kernel/qaction.h:218
#20 QToolButton::nextCheckState (this=0x8cf6000) at widgets/qtoolbutton.cpp:1152
#21 0xb6a1a303 in QAbstractButtonPrivate::click (this=this@entry=0x8cf6018) at widgets/qabstractbutton.cpp:530
#22 0xb6a1a44e in QAbstractButton::mouseReleaseEvent (this=this@entry=0x8cf6000, e=e@entry=0xbfa97de4) at widgets/qabstractbutton.cpp:1123
#23 0xb6aed177 in QToolButton::mouseReleaseEvent (this=0x8cf6000, e=0xbfa97de4) at widgets/qtoolbutton.cpp:723
#24 0xb665e66a in QWidget::event (this=this@entry=0x8cf6000, event=event@entry=0xbfa97de4) at kernel/qwidget.cpp:8389
#25 0xb6a1b452 in QAbstractButton::event (this=this@entry=0x8cf6000, e=e@entry=0xbfa97de4) at widgets/qabstractbutton.cpp:1082
#26 0xb6aed264 in QToolButton::event (this=0x8cf6000, event=0xbfa97de4) at widgets/qtoolbutton.cpp:1168
#27 0xb66044c4 in QApplicationPrivate::notify_helper (this=0x8a98c88, receiver=receiver@entry=0x8cf6000, e=0xbfa97de4) at kernel/qapplication.cpp:4570
#28 0xb660c215 in QApplication::notify (this=0xbfa9836c, receiver=receiver@entry=0x8cf6000, e=e@entry=0xbfa97de4) at kernel/qapplication.cpp:4113
#29 0xb715f074 in KApplication::notify (this=0xbfa9836c, receiver=0x8cf6000, event=0xbfa97de4) at ../../kdeui/kernel/kapplication.cpp:311
#30 0xb601daca in QCoreApplication::notifyInternal (this=0xbfa9836c, receiver=receiver@entry=0x8cf6000, event=event@entry=0xbfa97de4) at kernel/qcoreapplication.cpp:953
#31 0xb660a821 in sendSpontaneousEvent (event=0xbfa97de4, receiver=0x8cf6000) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#32 QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x8cf6000, event=0xbfa97de4, alienWidget=0x8cf6000, nativeWidget=0x8b72348, buttonDown=buttonDown@entry=0xb6f73cc4 <qt_button_down>, lastMouseReceiver=..., spontaneous=spontaneous@entry=true) at kernel/qapplication.cpp:3176
#33 0xb668b838 in QETWidget::translateMouseEvent (this=0x8b72348, event=event@entry=0xbfa97ffc) at kernel/qapplication_x11.cpp:4540
#34 0xb6689f00 in QApplication::x11ProcessEvent (this=0xbfa9836c, event=event@entry=0xbfa97ffc) at kernel/qapplication_x11.cpp:3663
#35 0xb66b5974 in x11EventSourceDispatch (s=0x8a991b0, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#36 0xb3246313 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#37 0xb3246598 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#38 0xb3246658 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#39 0xb604d6df in QEventDispatcherGlib::processEvents (this=this@entry=0x8a629d0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#40 0xb66b5a2e in QGuiEventDispatcherGlib::processEvents (this=0x8a629d0, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#41 0xb601c483 in QEventLoop::processEvents (this=this@entry=0xbfa982b8, flags=...) at kernel/qeventloop.cpp:149
#42 0xb601c7a9 in QEventLoop::exec (this=this@entry=0xbfa982b8, flags=...) at kernel/qeventloop.cpp:204
#43 0xb602259e in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#44 0xb6602954 in QApplication::exec () at kernel/qapplication.cpp:3828
#45 0x080504a0 in main (argc=5, argv=0xbfa98444) at ../../../systemsettings/app/main.cpp:49

Reported using DrKonqi