Version:           0.7svn958040 (using KDE 4.2.3)
Installed from:    SuSE RPMs

KNetworkManger shows (in General settings) options related to wireless which are not relevant as my desktop computer does not have wifi card.

I decided to have a look into configuration where I found "Show wireless connections" which was enabled.

After disabling it and clicking ok I've got:
Program: Przestrzeń robocza Plazmy (plasma), sygnał SIGSEGV
[Current thread is 1 (Thread 0xb5334700 (LWP 7139))]

Thread 4 (Thread 0xa99b6b90 (LWP 7154)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb6614c35 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb6674872 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#3  0xb7a730d2 in ?? () from /usr/lib/libQtNetwork.so.4
#4  0xb667385e in ?? () from /usr/lib/libQtCore.so.4
#5  0xb66111b5 in start_thread () from /lib/libpthread.so.0
#6  0xb64533be in clone () from /lib/libc.so.6

Thread 3 (Thread 0xa8fffb90 (LWP 7167)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb6614c35 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb6674872 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#3  0xa9e86d6a in ?? () from /usr/lib/kde4/plasma_wallpaper_image.so
#4  0xb667385e in ?? () from /usr/lib/libQtCore.so.4
#5  0xb66111b5 in start_thread () from /lib/libpthread.so.0
#6  0xb64533be in clone () from /lib/libc.so.6

Thread 2 (Thread 0xa82ebb90 (LWP 7185)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb6614f62 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb667484c in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#3  0xb66699c6 in ?? () from /usr/lib/libQtCore.so.4
#4  0xb667385e in ?? () from /usr/lib/libQtCore.so.4
#5  0xb66111b5 in start_thread () from /lib/libpthread.so.0
#6  0xb64533be in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb5334700 (LWP 7139)):
[KCrash Handler]
#6  InterfaceGroup::setNetworksLimit (this=0xffffffff, wlans=99) at /usr/src/debug/networkmanager/applet/interfacegroup.cpp:194
#7  0xa9b3ceaf in NetworkManagerApplet::configAccepted (this=0x82615a0) at /usr/src/debug/networkmanager/applet/networkmanager.cpp:258
#8  0xa9b40b7b in NetworkManagerApplet::qt_metacall (this=0x82615a0, _c=QMetaObject::InvokeMetaMethod, _id=7, _a=0xbfde2308) at /usr/src/debug/networkmanager/build/applet/networkmanager.moc:96
#9  0xb6778580 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#10 0xb6779302 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#11 0xb772d567 in KDialog::okClicked() () from /usr/lib/libkdeui.so.5
#12 0xb7730078 in KDialog::slotButtonClicked(int) () from /usr/lib/libkdeui.so.5
#13 0xb77313c4 in KDialog::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdeui.so.5
#14 0xb77f018a in KPageDialog::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdeui.so.5
#15 0xb771d9aa in KConfigDialog::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdeui.so.5
#16 0xb6778580 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#17 0xb6779302 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#18 0xb677c393 in QSignalMapper::mapped(int) () from /usr/lib/libQtCore.so.4
#19 0xb677cc1d in QSignalMapper::map(QObject*) () from /usr/lib/libQtCore.so.4
#20 0xb677ce0e in QSignalMapper::map() () from /usr/lib/libQtCore.so.4
#21 0xb677d74b in QSignalMapper::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#22 0xb6778580 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#23 0xb6778980 in QMetaObject::activate(QObject*, QMetaObject const*, int, int, void**) () from /usr/lib/libQtCore.so.4
#24 0xb6fc0621 in QAbstractButton::clicked(bool) () from /usr/lib/libQtGui.so.4
#25 0xb6d13d99 in ?? () from /usr/lib/libQtGui.so.4
#26 0xb6d15914 in ?? () from /usr/lib/libQtGui.so.4
#27 0xb6d15ba6 in QAbstractButton::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/libQtGui.so.4
#28 0xb6a2ba72 in QWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#29 0xb6d13c3e in QAbstractButton::event(QEvent*) () from /usr/lib/libQtGui.so.4
#30 0xb6dba2f0 in QPushButton::event(QEvent*) () from /usr/lib/libQtGui.so.4
#31 0xb69d38fc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#32 0xb69dc111 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#33 0xb77c10cd in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#34 0xb6763961 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#35 0xb69db39e in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&) () from /usr/lib/libQtGui.so.4
#36 0xb6a45756 in ?? () from /usr/lib/libQtGui.so.4
#37 0xb6a44b05 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#38 0xb6a6d0ca in ?? () from /usr/lib/libQtGui.so.4
#39 0xb57439c8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#40 0xb5747083 in ?? () from /usr/lib/libglib-2.0.so.0
#41 0xb5747241 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#42 0xb678dfb8 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#43 0xb6a6c7c5 in ?? () from /usr/lib/libQtGui.so.4
#44 0xb676201a in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#45 0xb67621da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#46 0xb6764895 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#47 0xb69d3777 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#48 0xb8065dc6 in kdemain () from /usr/lib/libkdeinit4_plasma.so
#49 0x08048782 in _start ()

PS. Why this option is enabled at all if I don't have any wifi card in my computer?