Version:            (using KDE 4.2.4)
OS:                Linux
Installed from:    Slackware Packages

When shutting down my system, Kontact occasionally crashes and gives me this traceback:

Application: Kontact (kontact), signal SIGSEGV
0x00007fcb6c267881 in nanosleep () from /lib64/libc.so.6

Thread 1 (Thread 0x7fcb7292b760 (LWP 2189)):
[KCrash Handler]
#5  0x00007fcb7172002b in Kontact::Plugin::icon () from /usr/lib64/libkontactinterfaces.so.4
#6  0x00007fcb7194a876 in Kontact::Model::data () from /usr/lib64/libkontactprivate.so.4
#7  0x00007fcb6d48b2db in QSortFilterProxyModel::data (this=<value optimized out>, index=@0x7fffb3df1ee0, role=1) at itemviews/qsortfilterproxymodel.cpp:1589
#8  0x00007fcb6d4b2ef5 in QStyledItemDelegate::initStyleOption (this=0x1a2bb00, option=0x7fffb3df1b20, index=@0x7fffb3df1ee0) at ../../include/QtCore/../../src/corelib/kernel/qabstractitemmodel.h:378
#9  0x00007fcb6d4b3f68 in QStyledItemDelegate::sizeHint (this=0x1a2bb00, option=@0x7fffb3df1c40, index=@0x7fffb3df1ee0) at itemviews/qstyleditemdelegate.cpp:443
#10 0x00007fcb7194ae69 in Kontact::Delegate::sizeHint () from /usr/lib64/libkontactprivate.so.4
#11 0x00007fcb6d4231b1 in QListViewPrivate::itemSize (this=0x1a9ca50, option=@0x7fffb3df1e20, index=@0x7fffb3df1ee0) at itemviews/qlistview.cpp:2103
#12 0x00007fcb6d4275e4 in QListView::updateGeometries (this=0x1a5f140) at itemviews/qlistview.cpp:1686
#13 0x00007fcb6cef48da in QWidget::event (this=0x1a5f140, event=0x7fffb3df2a50) at kernel/qwidget.cpp:7667
#14 0x00007fcb6d2c609b in QFrame::event (this=0x1a5f140, e=0x7fffb3df2a50) at widgets/qframe.cpp:559
#15 0x00007fcb6d4073ad in QAbstractItemView::viewportEvent (this=0x1a5f140, event=0x7fffb3df2a50) at itemviews/qabstractitemview.cpp:1471
#16 0x00007fcb6e273028 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x1a68010, event=0x7fffb3df2a50) at kernel/qcoreapplication.cpp:726
#17 0x00007fcb6ce9dd3c in QApplicationPrivate::notify_helper (this=0x1973c50, receiver=0x1a68010, e=0x7fffb3df2a50) at kernel/qapplication.cpp:4053
#18 0x00007fcb6cea45ae in QApplication::notify (this=0x7fffb3df7d60, receiver=0x1a68010, e=0x7fffb3df2a50) at kernel/qapplication.cpp:4022
#19 0x00007fcb6f0b42fb in KApplication::notify () from /usr/lib64/libkdeui.so.5
#20 0x00007fcb6e27358c in QCoreApplication::notifyInternal (this=0x7fffb3df7d60, receiver=0x1a68010, event=0x7fffb3df2a50) at kernel/qcoreapplication.cpp:610
#21 0x00007fcb6cf344b3 in QWidgetPrivate::setGeometry_sys (this=0x1aada90, x=<value optimized out>, y=3, w=<value optimized out>, h=0, isMove=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#22 0x00007fcb6cef3747 in QWidget::setGeometry (this=0x1a68010, r=@0x7fffb3df2c60) at kernel/qwidget.cpp:6204
#23 0x00007fcb6d35c0f4 in QAbstractScrollAreaPrivate::layoutChildren (this=0x1a9ca50) at widgets/qabstractscrollarea.cpp:459
#24 0x00007fcb6d35c706 in QAbstractScrollArea::event (this=0x1a5f140, e=0x1f899f0) at widgets/qabstractscrollarea.cpp:874
#25 0x00007fcb6d3ffd0b in QAbstractItemView::event (this=0x1a5f140, event=0x7fffb3df3370) at itemviews/qabstractitemview.cpp:1406
#26 0x00007fcb6ce9dd6d in QApplicationPrivate::notify_helper (this=0x1973c50, receiver=0x1a5f140, e=0x7fffb3df3370) at kernel/qapplication.cpp:4057
#27 0x00007fcb6cea45ae in QApplication::notify (this=0x7fffb3df7d60, receiver=0x1a5f140, e=0x7fffb3df3370) at kernel/qapplication.cpp:4022
#28 0x00007fcb6f0b42fb in KApplication::notify () from /usr/lib64/libkdeui.so.5
#29 0x00007fcb6e27358c in QCoreApplication::notifyInternal (this=0x7fffb3df7d60, receiver=0x1a5f140, event=0x7fffb3df3370) at kernel/qcoreapplication.cpp:610
#30 0x00007fcb6cf344b3 in QWidgetPrivate::setGeometry_sys (this=0x1a9ca50, x=<value optimized out>, y=0, w=<value optimized out>, h=0, isMove=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#31 0x00007fcb6cef3747 in QWidget::setGeometry (this=0x1a5f140, r=@0x7fffb3df3520) at kernel/qwidget.cpp:6204
#32 0x00007fcb6ced244c in QWidgetItem::setGeometry (this=0x1aa57e0, rect=<value optimized out>) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:970
#33 0x00007fcb6ceae4b6 in QBoxLayout::setGeometry (this=0x1a5f9d0, r=@0x7fffb3df3750) at kernel/qboxlayout.cpp:867
#34 0x00007fcb6cecd167 in QLayoutPrivate::doResize (this=0x1ab4440, r=@0x7fffb3df3ce4) at kernel/qlayout.cpp:637
#35 0x00007fcb6ce9dd2e in QApplicationPrivate::notify_helper (this=0x1973c50, receiver=0x1a992d0, e=0x7fffb3df3cd0) at kernel/qapplication.cpp:4048
#36 0x00007fcb6cea45ae in QApplication::notify (this=0x7fffb3df7d60, receiver=0x1a992d0, e=0x7fffb3df3cd0) at kernel/qapplication.cpp:4022
#37 0x00007fcb6f0b42fb in KApplication::notify () from /usr/lib64/libkdeui.so.5
#38 0x00007fcb6e27358c in QCoreApplication::notifyInternal (this=0x7fffb3df7d60, receiver=0x1a992d0, event=0x7fffb3df3cd0) at kernel/qcoreapplication.cpp:610
#39 0x00007fcb6cf344b3 in QWidgetPrivate::setGeometry_sys (this=0x1ab3ec0, x=<value optimized out>, y=0, w=<value optimized out>, h=0, isMove=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#40 0x00007fcb6cef3747 in QWidget::setGeometry (this=0x1a992d0, r=@0x7fffb3df3e90) at kernel/qwidget.cpp:6204
#41 0x00007fcb6d32a859 in QSplitterPrivate::setGeo (this=0x1ab45a0, sls=0x1aa6e20, p=0, s=84, allowCollapse=false) at widgets/qsplitter.cpp:702
#42 0x00007fcb6d32d4e3 in QSplitterPrivate::doResize (this=0x1ab45a0) at widgets/qsplitter.cpp:501
#43 0x00007fcb6cef48da in QWidget::event (this=0x1aa3100, event=0x7fffb3df46d0) at kernel/qwidget.cpp:7667
#44 0x00007fcb6ce9dd6d in QApplicationPrivate::notify_helper (this=0x1973c50, receiver=0x1aa3100, e=0x7fffb3df46d0) at kernel/qapplication.cpp:4057
#45 0x00007fcb6cea45ae in QApplication::notify (this=0x7fffb3df7d60, receiver=0x1aa3100, e=0x7fffb3df46d0) at kernel/qapplication.cpp:4022
#46 0x00007fcb6f0b42fb in KApplication::notify () from /usr/lib64/libkdeui.so.5
#47 0x00007fcb6e27358c in QCoreApplication::notifyInternal (this=0x7fffb3df7d60, receiver=0x1aa3100, event=0x7fffb3df46d0) at kernel/qcoreapplication.cpp:610
#48 0x00007fcb6cf344b3 in QWidgetPrivate::setGeometry_sys (this=0x1ab45a0, x=<value optimized out>, y=0, w=<value optimized out>, h=0, isMove=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#49 0x00007fcb6cef3747 in QWidget::setGeometry (this=0x1aa3100, r=@0x7fffb3df4880) at kernel/qwidget.cpp:6204
#50 0x00007fcb6ced244c in QWidgetItem::setGeometry (this=0x1aa7ec0, rect=<value optimized out>) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:970
#51 0x00007fcb6ceae4b6 in QBoxLayout::setGeometry (this=0x1aa8810, r=@0x7fffb3df4ab0) at kernel/qboxlayout.cpp:867
#52 0x00007fcb6cecd167 in QLayoutPrivate::doResize (this=0x1ab3260, r=@0x7fffb3df5044) at kernel/qlayout.cpp:637
#53 0x00007fcb6ce9dd2e in QApplicationPrivate::notify_helper (this=0x1973c50, receiver=0x1aa3260, e=0x7fffb3df5030) at kernel/qapplication.cpp:4048
#54 0x00007fcb6cea45ae in QApplication::notify (this=0x7fffb3df7d60, receiver=0x1aa3260, e=0x7fffb3df5030) at kernel/qapplication.cpp:4022
#55 0x00007fcb6f0b42fb in KApplication::notify () from /usr/lib64/libkdeui.so.5
#56 0x00007fcb6e27358c in QCoreApplication::notifyInternal (this=0x7fffb3df7d60, receiver=0x1aa3260, event=0x7fffb3df5030) at kernel/qcoreapplication.cpp:610
#57 0x00007fcb6cf344b3 in QWidgetPrivate::setGeometry_sys (this=0x1ab3450, x=<value optimized out>, y=70, w=<value optimized out>, h=0, isMove=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#58 0x00007fcb6cef3747 in QWidget::setGeometry (this=0x1aa3260, r=@0x7fffb3df5270) at kernel/qwidget.cpp:6204
#59 0x00007fcb6d370daa in QWidgetAnimator::animate (this=0x1a5dfc0, widget=0x0, _final_geometry=<value optimized out>, animate=<value optimized out>) at widgets/qwidgetanimator.cpp:141
#60 0x00007fcb6d2b7feb in QDockAreaLayout::apply (this=0x1a65fe8, animate=<value optimized out>) at widgets/qdockarealayout.cpp:3067
#61 0x00007fcb6d2e57d6 in QMainWindowLayout::applyState (this=0x1a65ef0, newState=@0x1a65f10, animate=false) at widgets/qmainwindowlayout.cpp:1926
#62 0x00007fcb6d2e5fd5 in QMainWindowLayout::setGeometry (this=0x1a65ef0, _r=<value optimized out>) at widgets/qmainwindowlayout.cpp:1434
#63 0x00007fcb6cecd167 in QLayoutPrivate::doResize (this=0x1a65df0, r=@0x7fffb3df5520) at kernel/qlayout.cpp:637
#64 0x00007fcb6cecd2be in QLayout::activate (this=0x1a65ef0) at kernel/qlayout.cpp:1210
#65 0x00007fcb6ce9dd2e in QApplicationPrivate::notify_helper (this=0x1973c50, receiver=0x1ab15f0, e=0x7fffb3df5ce0) at kernel/qapplication.cpp:4048
#66 0x00007fcb6cea45ae in QApplication::notify (this=0x7fffb3df7d60, receiver=0x1ab15f0, e=0x7fffb3df5ce0) at kernel/qapplication.cpp:4022
#67 0x00007fcb6f0b42fb in KApplication::notify () from /usr/lib64/libkdeui.so.5
#68 0x00007fcb6e27358c in QCoreApplication::notifyInternal (this=0x7fffb3df7d60, receiver=0x1ab15f0, event=0x7fffb3df5ce0) at kernel/qcoreapplication.cpp:610
#69 0x00007fcb6cf05221 in QETWidget::translateConfigEvent (this=0x1ab15f0, event=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#70 0x00007fcb6cf154bd in QApplication::x11ProcessEvent (this=0x7fffb3df7d60, event=0x7fffb3df76a0) at kernel/qapplication_x11.cpp:3471
#71 0x00007fcb6cf3d8e4 in x11EventSourceDispatch (s=0x196b350, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#72 0x00007fcb67f9328b in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#73 0x00007fcb67f96a4d in ?? () from /usr/lib64/libglib-2.0.so.0
#74 0x00007fcb67f96c0b in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#75 0x00007fcb6e29fdbf in QEventDispatcherGlib::processEvents (this=0x1972f20, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:324
#76 0x00007fcb6cf3d02f in QGuiEventDispatcherGlib::processEvents (this=0x7fffb3df18a0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#77 0x00007fcb6e2749f9 in QCoreApplication::processEvents (flags={i = -1277199808}) at kernel/qcoreapplication.cpp:803
#78 0x00007fcb4b73382e in KNCleanUp::start () from /usr/lib64/libknodecommon.so.4
#79 0x00007fcb4b777578 in KNMainWidget::prepareShutdown () from /usr/lib64/libknodecommon.so.4
#80 0x00007fcb4b9da54d in KNodePart::~KNodePart () from /usr/lib64/kde4/knodepart.so
#81 0x00007fcb71720efe in Kontact::Plugin::~Plugin () from /usr/lib64/libkontactinterfaces.so.4
#82 0x00007fcb5beaa0b5 in KNodePlugin::~KNodePlugin () from /usr/lib64/kde4/kontact_knodeplugin.so
#83 0x00007fcb71941d1e in Kontact::MainWindow::~MainWindow () from /usr/lib64/libkontactprivate.so.4
#84 0x000000000040473e in main ()

As the traceback mentions KNode, I've tried running KNode separately from Kontact, but I've not been able to reproduce this with just KNode.

If it's any help, I'm running Kontact with Mail (KMail), Usenet (KNode) and RSS Feed (Akgreagator) enabled.