Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.6.0
Operating System: Linux 2.6.32-gentoo-r1 x86_64

What I was doing when the application crashed:
I was copying about 100megs of data to a slow USB thumb drive and watching the progress notification from the system tray when it spontaneously crashed at the end of the transfer. 

I can't be certain if the transfer was actually complete and the system tray was destroying resources since it no longer needed to track the copy operation or if the crash happened before the copy was finished. I had the mouse in the vicinity of the progress notification so it's possible a tooltip was being created as a resource was being destroyed. I'll attach GDB and try a few more copy operations and see if I can recreate the crash.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib64/libgobject-2.0.so.0.2200.3-gdb.py", line 9, in <module>
    from gobject import register
  File "/usr/share/glib-2.0/gdb/gobject.py", line 3, in <module>
    import gdb.backtrace
ImportError: No module named backtrace
The current source language is "auto; currently asm".
[Current thread is 1 (Thread 0x7ffd8e901760 (LWP 4504))]

Thread 3 (Thread 0x7ffd6fcef710 (LWP 4508)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007ffd8e3334db in QWaitConditionPrivate::wait (this=<value optimized out>, mutex=0x1a60788, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:87
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x1a60788, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:159
#3  0x00007ffd8a798a2c in QHostInfoAgent::run (this=0x1a60770) at kernel/qhostinfo.cpp:252
#4  0x00007ffd8e332515 in QThreadPrivate::start (arg=0x1a60770) at thread/qthread_unix.cpp:244
#5  0x00007ffd8e0a7894 in start_thread (arg=<value optimized out>) at pthread_create.c:297
#6  0x00007ffd8baa6f9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7ffd673c5710 (LWP 4515)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007ffd6dd91506 in WTF::TCMalloc_PageHeap::scavengerThread (this=0x7ffd6e051440) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2304
#2  0x00007ffd6dd91529 in WTF::TCMalloc_PageHeap::runScavengerThread (context=0x7ffd6e05f50c) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1438
#3  0x00007ffd8e0a7894 in start_thread (arg=<value optimized out>) at pthread_create.c:297
#4  0x00007ffd8baa6f9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7ffd8e901760 (LWP 4504)):
[KCrash Handler]
#5  0x00007ffd8607c460 in Plasma::ExtenderItem::config (this=0x20ff110) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extenderitem.cpp:153
#6  0x00007ffd8607e172 in Plasma::ExtenderItem::isGroup (this=0x3a) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extenderitem.cpp:341
#7  0x00007ffd86074455 in Plasma::Extender::isEmpty (this=<value optimized out>) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extender.cpp:717
#8  0x00007ffd860744b9 in Plasma::ExtenderPrivate::updateEmptyExtenderLabel (this=0x192bc30) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extender.cpp:681
#9  0x00007ffd86074a72 in Plasma::Extender::itemRemovedEvent (this=0x192a830, item=<value optimized out>) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extender.cpp:447
#10 0x00007ffd86074196 in Plasma::ExtenderPrivate::removeExtenderItem (this=0x192bc30, item=0x28aff70) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extender.cpp:562
#11 0x00007ffd8607d3c4 in Plasma::ExtenderItem::destroy (this=0x28aff70) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/extenderitem.cpp:445
#12 0x00007ffd8607f368 in Plasma::ExtenderItem::qt_metacall (this=0x28aff70, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffba8fc990)
    at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4_build/plasma/extenderitem.moc:99
#13 0x00007ffd8e437203 in QMetaObject::activate (sender=0x2831680, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x26ce514) at kernel/qobject.cpp:3286
#14 0x00007ffd860d3a68 in Plasma::IconWidget::mouseReleaseEvent (this=0x2831680, event=<value optimized out>)
    at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/plasma/widgets/iconwidget.cpp:1178
#15 0x00007ffd8c75e294 in QGraphicsItem::sceneEvent (this=0x2831690, event=0x3a) at graphicsview/qgraphicsitem.cpp:6531
#16 0x00007ffd8c7782f8 in QGraphicsScenePrivate::sendMouseEvent (this=0x1690ba0, mouseEvent=0x7fffba8fd300) at graphicsview/qgraphicsscene.cpp:1212
#17 0x00007ffd8c778be6 in QGraphicsScene::mouseReleaseEvent (this=<value optimized out>, mouseEvent=0x7fffba8fd300) at graphicsview/qgraphicsscene.cpp:4007
#18 0x00007ffd8c781f30 in QGraphicsScene::event (this=0x16899e0, event=0x7fffba8fd300) at graphicsview/qgraphicsscene.cpp:3348
#19 0x00007ffd8c1e3b9c in QApplicationPrivate::notify_helper (this=0x15a3310, receiver=0x16899e0, e=0x7fffba8fd300) at kernel/qapplication.cpp:4242
#20 0x00007ffd8c1ec3da in QApplication::notify (this=0x156e820, receiver=<value optimized out>, e=0x7fffba8fd300) at kernel/qapplication.cpp:4125
#21 0x00007ffd8cdd3466 in KApplication::notify (this=0x156e820, receiver=0x16899e0, event=0x7fffba8fd300)
    at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/kdeui/kernel/kapplication.cpp:302
#22 0x00007ffd8e4245bb in QCoreApplication::notifyInternal (this=0x156e820, receiver=0x16899e0, event=0x7fffba8fd300) at kernel/qcoreapplication.cpp:704
#23 0x00007ffd8c7a1a85 in QGraphicsView::mouseReleaseEvent (this=0x1aeabe0, event=0x7fffba8fdeb0) at graphicsview/qgraphicsview.cpp:3219
#24 0x00007ffd8c238449 in QWidget::event (this=0x1aeabe0, event=0x7fffba8fdeb0) at kernel/qwidget.cpp:7974
#25 0x00007ffd8c58b7e6 in QFrame::event (this=0x1aeabe0, e=0x7fffba8fdeb0) at widgets/qframe.cpp:557
#26 0x00007ffd8c79e92b in QGraphicsView::viewportEvent (this=0x1aeabe0, event=0x7fffba8fdeb0) at graphicsview/qgraphicsview.cpp:2747
#27 0x00007ffd8e4239f6 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x1ae9830, event=0x7fffba8fdeb0) at kernel/qcoreapplication.cpp:819
#28 0x00007ffd8c1e3b6c in QApplicationPrivate::notify_helper (this=0x15a3310, receiver=0x1ae9830, e=0x7fffba8fdeb0) at kernel/qapplication.cpp:4238
#29 0x00007ffd8c1ecb71 in QApplication::notify (this=<value optimized out>, receiver=0x1ae9830, e=0x7fffba8fdeb0) at kernel/qapplication.cpp:3822
#30 0x00007ffd8cdd3466 in KApplication::notify (this=0x156e820, receiver=0x1ae9830, event=0x7fffba8fdeb0)
    at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/kdeui/kernel/kapplication.cpp:302
#31 0x00007ffd8e4245bb in QCoreApplication::notifyInternal (this=0x156e820, receiver=0x1ae9830, event=0x7fffba8fdeb0) at kernel/qcoreapplication.cpp:704
#32 0x00007ffd8c1ebbcb in QCoreApplication::sendEvent (receiver=<value optimized out>, event=0x7fffba8fdeb0, alienWidget=0x1ae9830, nativeWidget=0x1aba6d0, buttonDown=0x26ce4d0, 
    lastMouseReceiver=<value optimized out>, spontaneous=true) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#33 QApplicationPrivate::sendMouseEvent (receiver=<value optimized out>, event=0x7fffba8fdeb0, alienWidget=0x1ae9830, nativeWidget=0x1aba6d0, buttonDown=0x26ce4d0, 
    lastMouseReceiver=<value optimized out>, spontaneous=true) at kernel/qapplication.cpp:2956
#34 0x00007ffd8c25b00b in QETWidget::translateMouseEvent (this=0x1aba6d0, event=<value optimized out>) at kernel/qapplication_x11.cpp:4368
#35 0x00007ffd8c25a1ba in QApplication::x11ProcessEvent (this=<value optimized out>, event=0x7fffba8fe660) at kernel/qapplication_x11.cpp:3501
#36 0x00007ffd8c280804 in x11EventSourceDispatch (s=0x15a6890, callback=<value optimized out>, user_data=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:146
#37 0x00007ffd8b321e3d in g_main_dispatch (context=0x15a5920) at gmain.c:1960
#38 IA__g_main_context_dispatch (context=0x15a5920) at gmain.c:2513
#39 0x00007ffd8b3257f8 in g_main_context_iterate (context=0x15a5920, block=<value optimized out>, dispatch=<value optimized out>, self=<value optimized out>) at gmain.c:2591
#40 0x00007ffd8b325920 in IA__g_main_context_iteration (context=0x15a5920, may_block=1) at gmain.c:2654
#41 0x00007ffd8e44da03 in QEventDispatcherGlib::processEvents (this=0x1529f70, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:407
#42 0x00007ffd8c28011e in QGuiEventDispatcherGlib::processEvents (this=0x7fffba8fc620, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#43 0x00007ffd8e422f12 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#44 0x00007ffd8e4232e4 in QEventLoop::exec (this=0x7fffba8fe980, flags=) at kernel/qeventloop.cpp:201
#45 0x00007ffd8e426fcb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#46 0x00007ffd8293f99f in kdemain (argc=<value optimized out>, argv=<value optimized out>)
    at /var/tmp/portage/kde-base/plasma-workspace-4.3.4/work/plasma-workspace-4.3.4/plasma/shells/desktop/main.cpp:50
#47 0x0000000000406ce5 in launch (argc=1, _name=<value optimized out>, args=<value optimized out>, cwd=<value optimized out>, envc=0, envs=<value optimized out>, reset_env=false, tty=0x0, 
    avoid_loops=false, startup_id_str=0x40a11d "0") at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/kinit/kinit.cpp:677
#48 0x00000000004079a0 in handle_launcher_request (sock=8, who=<value optimized out>) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/kinit/kinit.cpp:1169
#49 0x0000000000407ee0 in handle_requests (waitForPid=0) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/kinit/kinit.cpp:1362
#50 0x0000000000408a81 in main (argc=2, argv=<value optimized out>, envp=<value optimized out>) at /var/tmp/portage/kde-base/kdelibs-4.3.4/work/kdelibs-4.3.4/kinit/kinit.cpp:1793

Reported using DrKonqi