Version:            (using KDE 4.3.0)
OS:                Linux
Installed from:    Fedora RPMs

GoTo System Settings-> Network Settings -> Network Settings

Right click on text area provided under 'Network Interfaces' tab. System Settings will crash. Reproduced on two different machines.

Here is the back trace

[...]

Application: System Settings (systemsettings), signal: Segmentation fault
[KCrash Handler]
#6  0x024677f2 in ?? () from /usr/lib/kde4/kcm_knetworkconfmodule.so
#7  0x0246eea6 in ?? () from /usr/lib/kde4/kcm_knetworkconfmodule.so
#8  0x02ddc058 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#9  0x02ddcce2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#10 0x023d450f in K3ListView::contextMenu () from /usr/lib/libkde3support.so.4
#11 0x023d454f in K3ListView::emitContextMenu () from /usr/lib/libkde3support.so.4
#12 0x023dc26c in K3ListView::qt_metacall () from /usr/lib/libkde3support.so.4
#13 0x02ddc058 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#14 0x02ddcce2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#15 0x029c9b6f in Q3ListView::rightButtonPressed () from /usr/lib/libQt3Support.so.4
#16 0x02859768 in Q3ListView::contentsMousePressEventEx () from /usr/lib/libQt3Support.so.4
#17 0x02859cb4 in Q3ListView::contentsMousePressEvent () from /usr/lib/libQt3Support.so.4
#18 0x023d877d in K3ListView::contentsMousePressEvent () from /usr/lib/libkde3support.so.4
#19 0x028b6d31 in Q3ScrollView::viewportMousePressEvent () from /usr/lib/libQt3Support.so.4
#20 0x028b8910 in Q3ScrollView::eventFilter () from /usr/lib/libQt3Support.so.4
#21 0x02854606 in Q3ListView::eventFilter () from /usr/lib/libQt3Support.so.4
#22 0x02dc5b1a in QCoreApplicationPrivate::sendThroughObjectEventFilters () from /usr/lib/libQtCore.so.4
#23 0x010cc73a in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#24 0x010d53e1 in QApplication::notify () from /usr/lib/libQtGui.so.4
#25 0x0082196d in KApplication::notify () from /usr/lib/libkdeui.so.5
#26 0x02dc68fb in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#27 0x010d444e in QApplicationPrivate::sendMouseEvent () from /usr/lib/libQtGui.so.4
#28 0x011444ce in ?? () from /usr/lib/libQtGui.so.4
#29 0x0114388d in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#30 0x0116d2ea in ?? () from /usr/lib/libQtGui.so.4
#31 0x0402e258 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#32 0x04031903 in ?? () from /lib/libglib-2.0.so.0
#33 0x04031ac1 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#34 0x02df2188 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#35 0x0116c9e5 in ?? () from /usr/lib/libQtGui.so.4
#36 0x02dc4f2a in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#37 0x02dc5372 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#38 0x02dc7819 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#39 0x010cc5d7 in QApplication::exec () from /usr/lib/libQtGui.so.4
#40 0x08052634 in _start ()

[...]