Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.1 (KDE 4.3.1) "release 6"
Qt Version: 4.5.3
Operating System: Linux 2.6.31.12-0.1-default i686
Distribution: "openSUSE 11.2 (i586)"

What I was doing when the application crashed:
1. Start with a new user. Default desktop is a "Folder" displaying the icons from things that are in ~/Desktop

2. Right-Click on the desktop and change the setting from "Desktop" to "Folder View". The icons now appear standalone on the desktop.

3. Right-Click again but this time, change the setting to "Desktop". Icons disappear but no "Folder" is displayed.

4. Right-Click and select "Add Widget", add "Folder View". Up pops a small, rectangular "button" entitled "Desktop". Delete it.

5. Right-Click, "Add Widget", "Folder View". Up pops a "Folder" entitled "home" displaying some of the contents of the home dir.

6. Right-Click Up and change settings to "Folder View". Icons reappear.

7. Right-Click, "Add Widget" "Folder View". Nothing happens. Repeat. Nothing happens.

8. Right Click and change settings to "Desktop". Icons disappear.

9. Right Click, "Add Widget" "Folder View". Up pops a "Folder" entitled "home" and showing some of the contents of the home dir. Delete it.

10. Right Click and change settings to "Folder View". Icons reappear.

11. Repeat 8.

12. Repeat 9. When the "Folder" appears, Right Click and change settings to "Folder View" and "Apply". Both "Folders" momentarily go blank, the icons reappear, both "Folders" show home dir contents. Go to "Location" and set "Specify a folder" to ~/Desktop. Nothing happens.

11. Delete the second "Home" "Folder".

12. Right Click, settings = "Desktop". Icons gone.

13. Right Click....Boom!

NB. When I was doing this the first time. I was able to have a "Folder" that displayed icons from the ~/Desktop directory. This time, I was not so clearly something I did before, I don't fully recall. But it's crashed again whilst going through all the steps reported here so I hope it's still useful.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb55ca700 (LWP 3831))]

Thread 2 (Thread 0xa8866b70 (LWP 3833)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb7468d95 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb74c8750 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#3  0xb5c17a04 in ?? () from /usr/lib/libQtNetwork.so.4
#4  0xb74c7623 in ?? () from /usr/lib/libQtCore.so.4
#5  0xb74646e5 in start_thread () from /lib/libpthread.so.0
#6  0xb7464600 in ?? () from /lib/libpthread.so.0

Thread 1 (Thread 0xb55ca700 (LWP 3831)):
[KCrash Handler]
#6  0xb6760a67 in QGraphicsItem::isWidget() const () from /usr/lib/libQtGui.so.4
#7  0xb6763962 in QGraphicsItem::isWindow() const () from /usr/lib/libQtGui.so.4
#8  0xb679b2af in QGraphicsScene::event(QEvent*) () from /usr/lib/libQtGui.so.4
#9  0xb61628fc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#10 0xb616a34e in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#11 0xb6ba0ce1 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#12 0xb75be32e in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#13 0xb67ace68 in QGraphicsView::viewportEvent(QEvent*) () from /usr/lib/libQtGui.so.4
#14 0xb65f9786 in ?? () from /usr/lib/libQtGui.so.4
#15 0xb75bd50e in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#16 0xb61628d0 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#17 0xb616a29e in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#18 0xb6ba0ce1 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#19 0xb75be32e in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#20 0xb61b9d5f in QWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#21 0xb6556bb5 in QFrame::event(QEvent*) () from /usr/lib/libQtGui.so.4
#22 0xb65f7bfa in QAbstractScrollArea::event(QEvent*) () from /usr/lib/libQtGui.so.4
#23 0xb67acc58 in QGraphicsView::event(QEvent*) () from /usr/lib/libQtGui.so.4
#24 0xb61628fc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#25 0xb616a29e in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#26 0xb6ba0ce1 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#27 0xb75be32e in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#28 0xb616da64 in QApplication::setActiveWindow(QWidget*) () from /usr/lib/libQtGui.so.4
#29 0xb61d96cb in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#30 0xb6204b68 in ?? () from /usr/lib/libQtGui.so.4
#31 0xb5d3d4c2 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#32 0xb5d40d98 in ?? () from /usr/lib/libglib-2.0.so.0
#33 0xb5d40ebe in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#34 0xb75ea011 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#35 0xb620429a in ?? () from /usr/lib/libQtGui.so.4
#36 0xb75bc98d in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#37 0xb75bcdd9 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#38 0xb75bf270 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#39 0xb6162774 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#40 0xb40b4b49 in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#41 0x0804e147 in _start ()

Reported using DrKonqi