Application: systemsettings (1.0)
KDE Platform Version: 4.8.4 (4.8.4)
Qt Version: 4.8.2
Operating System: Linux 3.2.0-4-amd64 x86_64
Distribution: LMDE Cinnamon Edition

-- Information about the crash:
- What I was doing when the application crashed:
I was adding buttons and removing spaces from the titlebar buttons in System Settings.  I was adding custom button options such as shade and keep above windows and trying to remove the spaces between the maximise and close application buttons.  No matter what I added or removed, the application crashed once I clicked on OK.  

I repeated this several times trying to remove or add different buttons and each time the application crashed.   Any application change that didn't involve "Use custom titlebar button positions" worked fine.  Even ticking the custom titlebar button positions and not making any changes after that caused it to crash once the OK button was pressed.

- Custom settings of the application:
In Workspace Appearance Settings, Window Decorations, Configure Buttons, the "use custom titlebar button positions" option was ticked.

The crash can be reproduced every time.

-- Backtrace:
Application: System Settings (systemsettings), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#5  0x00007fdc5c0fa818 in QGraphicsDropShadowEffect::draw(QPainter*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#6  0x00007fdc5c08f39b in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#7  0x00007fdc5c08e8d5 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#8  0x00007fdc5c08f405 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#9  0x00007fdc5c08fc88 in QGraphicsScene::drawItems(QPainter*, int, QGraphicsItem**, QStyleOptionGraphicsItem const*, QWidget*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#10 0x00007fdc5c07d478 in QGraphicsScene::render(QPainter*, QRectF const&, QRectF const&, Qt::AspectRatioMode) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#11 0x00007fdc40350ee1 in ?? () from /usr/lib/kde4/kcm_kwindecoration.so
#12 0x00007fdc403518d4 in ?? () from /usr/lib/kde4/kcm_kwindecoration.so
#13 0x00007fdc4034521f in ?? () from /usr/lib/kde4/kcm_kwindecoration.so
#14 0x00007fdc5ae2354f in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#15 0x00007fdc5c0fff52 in QAbstractButton::clicked(bool) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#16 0x00007fdc5be5408e in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#17 0x00007fdc5be548c0 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#18 0x00007fdc5be54b2c in QAbstractButton::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#19 0x00007fdc5bae9e10 in QWidget::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#20 0x00007fdc5ba9a70c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#21 0x00007fdc5ba9f3eb in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#22 0x00007fdc5c7cd886 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#23 0x00007fdc5ae0db5e in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#24 0x00007fdc5ba9b54b in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#25 0x00007fdc5bb15fc4 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#26 0x00007fdc5bb14d51 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#27 0x00007fdc5bb3bbc2 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#28 0x00007fdc57fb8355 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fdc57fb8688 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fdc57fb8744 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007fdc5ae3c276 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#32 0x00007fdc5bb3b83e in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#33 0x00007fdc5ae0c8af in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#34 0x00007fdc5ae0cb38 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#35 0x00007fdc5ae11cf8 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#36 0x000000000040b1ee in ?? ()
#37 0x00007fdc5a61eead in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#38 0x000000000040b245 in _start ()

Reported using DrKonqi