The backtrace lacks of some useful information. You need to install kdepim-dbg and kdepimlibs-dbg. Try to remember what were you doing when Kontact crashed to try to reproduce the sitution and get a new backtrace.
Thanks

I have the same bug when I close the application:

Application: Kontact (kontact), signal SIGSEGV
0x00007feaa08f8b51 in nanosleep () from /lib/libc.so.6
[Current thread is 1 (Thread 0x7feaa3148750 (LWP 4628))]

Thread 2 (Thread 0x7fea85501950 (LWP 7915)):
#0  0x00007feaa0921d62 in select () from /lib/libc.so.6
#1  0x00007feaa1b3f756 in QProcessManager::run (this=0x1b84840) at
io/qprocess_unix.cpp:301
#2  0x00007feaa1a77162 in QThreadPrivate::start (arg=0x1b84840) at
thread/qthread_unix.cpp:185
#3  0x00007fea9b11bfaa in start_thread () from /lib/libpthread.so.0
#4  0x00007feaa092850d in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7feaa3148750 (LWP 4628)):
[KCrash Handler]
#5  Kontact::Plugin::icon (this=0x21025b0) at
/usr/include/qt4/QtCore/qstring.h:670
#6  0x00007feaa2e5e9e6 in Kontact::Model::data (this=<value optimized out>,
index=@0x7fffab283e70, role=1) at ../../../kontact/src/iconsidepane.cpp:149
#7  0x00007feaa1570423 in QSortFilterProxyModel::data (this=<value optimized
out>, index=@0x7fffab284560, role=1) at
itemviews/qsortfilterproxymodel.cpp:1505
#8  0x00007feaa15933b5 in QStyledItemDelegate::initStyleOption (this=0x1d08ac0,
option=0x7fffab2840b0, index=@0x7fffab284560) at
../../include/QtCore/../../src/corelib/kernel/qabstractitemmodel.h:367
#9  0x00007feaa15942a8 in QStyledItemDelegate::sizeHint (this=0x1d08ac0,
option=@0x7fffab2841d0, index=@0x7fffab284560) at
itemviews/qstyleditemdelegate.cpp:435
#10 0x00007feaa2e5f049 in Kontact::Delegate::sizeHint (this=0x1d08ac0,
option=@0x7fffab284370, index=@0x7fffab284560) at
../../../kontact/src/iconsidepane.cpp:224
#11 0x00007feaa15106d1 in QListViewPrivate::itemSize (this=0x1b93710,
option=@0x7fffab284370, index=@0x7fffab284560) at itemviews/qlistview.cpp:2077
#12 0x00007feaa1510b83 in QStaticListViewBase::indexToListViewItem
(this=0x1b964a0, index=@0x7fffab284560) at
../../include/QtGui/private/../../../src/gui/itemviews/qlistview_p.h:414
#13 0x00007feaa1510cda in QListViewPrivate::indexToListViewItem (this=<value
optimized out>, index=<value optimized out>) at itemviews/qlistview.cpp:2009
#14 0x00007feaa1511159 in QListView::rectForIndex (this=0x1b93690,
index=@0x7fffab284560) at itemviews/qlistview.cpp:1412
#15 0x00007feaa151124c in QListView::visualRect (this=0x7fffab283e30,
index=@0x21025b0) at itemviews/qlistview.cpp:570
#16 0x00007feaa150fc03 in QListView::indexAt (this=0x1b93690,
p=@0x7fffab284c64) at itemviews/qlistview.cpp:1202
#17 0x00007feaa14fa2ac in QAbstractItemView::viewportEvent (this=0x1b93690,
event=0x7fffab284c50) at itemviews/qabstractitemview.cpp:1394
#18 0x00007feaa1b5e668 in
QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized
out>, receiver=0x1b960f0, event=0x7fffab284c50) at
kernel/qcoreapplication.cpp:694
#19 0x00007feaa1083a2c in QApplicationPrivate::notify_helper (this=0x1b7f700,
receiver=0x1b960f0, e=0x7fffab284c50) at kernel/qapplication.cpp:3799
#20 0x00007feaa108c3ee in QApplication::notify (this=<value optimized out>,
receiver=<value optimized out>, e=0x7fffab285100) at
kernel/qapplication.cpp:3553
#21 0x00007feaa24d4fab in KApplication::notify (this=0x7fffab2875d0,
receiver=0x1b960f0, event=0x7fffab285100) at
../../kdeui/kernel/kapplication.cpp:307
#22 0x00007feaa1b5f391 in QCoreApplication::notifyInternal
(this=0x7fffab2875d0, receiver=0x1b960f0, event=0x7fffab285100) at
kernel/qcoreapplication.cpp:587
#23 0x00007feaa108b3e8 in QApplicationPrivate::sendMouseEvent
(receiver=0x1b960f0, event=0x7fffab285100, alienWidget=0x0,
nativeWidget=0x1b960f0, buttonDown=<value optimized out>, lastMouseReceiver=
    @0x7feaa1a090e0) at
../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:212
#24 0x00007feaa10ef939 in QETWidget::translateMouseEvent (this=0x1b960f0,
event=<value optimized out>) at kernel/qapplication_x11.cpp:4044
#25 0x00007feaa10eeb08 in QApplication::x11ProcessEvent (this=<value optimized
out>, event=0x7fffab2859c0) at kernel/qapplication_x11.cpp:3240
#26 0x00007feaa1115cb4 in x11EventSourceDispatch (s=0x1b84390, callback=0,
user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142
#27 0x00007fea9b369afb in g_main_context_dispatch () from
/usr/lib/libglib-2.0.so.0
#28 0x00007fea9b36d2bd in ?? () from /usr/lib/libglib-2.0.so.0
#29 0x00007fea9b36d47b in g_main_context_iteration () from
/usr/lib/libglib-2.0.so.0
#30 0x00007feaa1b8771f in QEventDispatcherGlib::processEvents (this=0x1b7ddf0,
flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319
#31 0x00007feaa111547f in QGuiEventDispatcherGlib::processEvents
(this=0x7fffab283e30, flags=<value optimized out>) at
kernel/qguieventdispatcher_glib.cpp:198
#32 0x00007feaa1b5dcb2 in QEventLoop::processEvents (this=<value optimized
out>, flags={i = -1423418192}) at kernel/qeventloop.cpp:143
#33 0x00007feaa1b5de3d in QEventLoop::exec (this=0x7fffab285e70, flags={i =
-1423417568}) at kernel/qeventloop.cpp:194
#34 0x00007feaa255ad0d in KWallet::Wallet::openWallet (name=@0x7fffab285fa0,
w=<value optimized out>, ot=KWallet::Wallet::Synchronous) at
../../kdeui/util/kwallet.cpp:248
#35 0x00007fea8b97c29c in KMKernel::wallet (this=0x22222e0) at
../../kmail/kmkernel.cpp:2296
#36 0x00007fea8b8fd236 in KMail::NetworkAccount::writeConfig (this=0x235b080,
config=@0x7fffab286630) at ../../kmail/networkaccount.cpp:208
#37 0x00007fea8b9037a6 in KMail::ImapAccountBase::writeConfig
(this=0x7fffab283e30, config=@0x21025b0) at ../../kmail/imapaccountbase.cpp:246
#38 0x00007fea8b89c93e in KMail::AccountManager::writeConfig (this=<value
optimized out>, withSync=false) at ../../kmail/accountmanager.cpp:63
#39 0x00007fea8b97bab3 in KMKernel::cleanup (this=0x22222e0) at
../../kmail/kmkernel.cpp:1633
#40 0x00007fea8c070fbc in ~KMailPart (this=0x2108dc0) at
../../kmail/kmail_part.cpp:141
#41 0x00007feaa2c3254e in ~Plugin (this=0x2086350, __vtt_parm=0x21025b0) at
../../kontactinterfaces/plugin.cpp:86
#42 0x00007fea8d107925 in ~KMailPlugin (this=0x7fffab283e30) at
../../../../kontact/plugins/kmail/kmail_plugin.cpp:150
#43 0x00007feaa2e53e8e in ~MainWindow (this=0x1b80550) at
../../../kontact/src/mainwindow.cpp:271
#44 0x00007feaa1b6e375 in QObject::event (this=0x1b80550, e=0x21025b0) at
kernel/qobject.cpp:1139
#45 0x00007feaa10d57d6 in QWidget::event (this=0x1b80550, event=0x23d2730) at
kernel/qwidget.cpp:7551
#46 0x00007feaa13ed44b in QMainWindow::event (this=0x1b80550, event=0x23d2730)
at widgets/qmainwindow.cpp:1268
#47 0x00007feaa25de9d8 in KXmlGuiWindow::event (this=0x7fffab283e30,
ev=0x21025b0) at ../../kdeui/xmlgui/kxmlguiwindow.cpp:131
#48 0x00007feaa1083a5d in QApplicationPrivate::notify_helper (this=0x1b7f700,
receiver=0x1b80550, e=0x23d2730) at kernel/qapplication.cpp:3803
#49 0x00007feaa108b7da in QApplication::notify (this=0x7fffab2875d0,
receiver=0x1b80550, e=0x23d2730) at kernel/qapplication.cpp:3768
#50 0x00007feaa24d4fab in KApplication::notify (this=0x7fffab2875d0,
receiver=0x1b80550, event=0x23d2730) at ../../kdeui/kernel/kapplication.cpp:307
#51 0x00007feaa1b5f391 in QCoreApplication::notifyInternal
(this=0x7fffab2875d0, receiver=0x1b80550, event=0x23d2730) at
kernel/qcoreapplication.cpp:587
#52 0x00007feaa1b6002a in QCoreApplicationPrivate::sendPostedEvents
(receiver=0x0, event_type=0, data=0x1b5d170) at
../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:209
#53 0x00007feaa1b87a93 in postEventSourceDispatch (s=<value optimized out>) at
../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:214
#54 0x00007fea9b369afb in g_main_context_dispatch () from
/usr/lib/libglib-2.0.so.0
#55 0x00007fea9b36d2bd in ?? () from /usr/lib/libglib-2.0.so.0
#56 0x00007fea9b36d47b in g_main_context_iteration () from
/usr/lib/libglib-2.0.so.0
#57 0x00007feaa1b8771f in QEventDispatcherGlib::processEvents (this=0x1b7ddf0,
flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319
#58 0x00007feaa111547f in QGuiEventDispatcherGlib::processEvents
(this=0x7fffab283e30, flags=<value optimized out>) at
kernel/qguieventdispatcher_glib.cpp:198
#59 0x00007feaa1b5dcb2 in QEventLoop::processEvents (this=<value optimized
out>, flags={i = -1423412240}) at kernel/qeventloop.cpp:143
#60 0x00007feaa1b5de3d in QEventLoop::exec (this=0x7fffab287430, flags={i =
-1423412160}) at kernel/qeventloop.cpp:194
#61 0x00007feaa1b602ed in QCoreApplication::exec () at
kernel/qcoreapplication.cpp:845
#62 0x0000000000404821 in main (argc=1, argv=0x7fffab287ba8) at
../../../kontact/src/main.cpp:218

Some analysis of the two backtraces:
* KMainWindow of Kontact gets deleted
* during that, some config (KCal::ResourceCalendar::save or KMail::NetworkAccount::writeConfig) needs to be saved
* this in turn may cause KWallet or KJob show a modal dialog
* somehow, these dialogs still have access to the KMainWindow of Kontact (maybe because they put the KMainWindow as the parent window?)
-> crash because some UI model data of the window has already been deleted in the destructor

Possible Solution: First save all config, then delete UI model data in KMainWindow destructor.

*** Bug 178949 has been marked as a duplicate of this bug. ***

*** Bug 196756 has been marked as a duplicate of this bug. ***

I got this one today with KDE 4.3 beta 2.

Created attachment 34755 [details]
Fix crash in ~MainWindow

The crash happens during deletion of the plugins (line 271), but the side bar model still references the icons of those.

Either the side bar model needs to be informed that a plugin has been deleted, or the side bar widget should be deleted before the plugins are deleted.

This patch uses the second method. Please implement the first method, if possible.

SVN commit 985891 by cfeck:

Fix crash due to accessing plugin icons in sidePane model

This fix is ugly; when the nested event loop is started, the window
will flash because of the removed sidePane. But it should not crash
anymore.

I will leave this bug open until someone can apply the better fix
(see comment #7)

CCBUG: 182176


 M  +3 -0      mainwindow.cpp  


WebSVN link: http://websvn.kde.org/?view=rev&revision=985891

*** Bug 198434 has been marked as a duplicate of this bug. ***

has this patch made it into KDE 4.3 RC1? because I still get those crashes...

Same here, on KDE on kubuntu 64bit. Packages are the latest available using adept 

This is the backtrace

Applicazione: Kontact (kontact), segnale SIGABRT
0x00007f10abd1ad21 in nanosleep () from /lib/libc.so.6
[Current thread is 0 (LWP 3938)]

Thread 3 (Thread 0x7f108e61c950 (LWP 4409)):
#0  0x00007f10abd51742 in select () from /lib/libc.so.6
#1  0x00007f10ac8c2f06 in ?? () from /usr/lib/libQtCore.so.4
#2  0x00007f10ac7fb952 in ?? () from /usr/lib/libQtCore.so.4
#3  0x00007f10a90c73ba in start_thread () from /lib/libpthread.so.0
#4  0x00007f10abd58fcd in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f109069a950 (LWP 16477)):
#0  0x00007f10a90cb56d in pthread_cond_timedwait@@GLIBC_2.3.2 () from
/lib/libpthread.so.0
#1  0x00007f10ac7fc917 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#2  0x00007f10ac7f2409 in ?? () from /usr/lib/libQtCore.so.4
#3  0x00007f10ac7fb952 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007f10a90c73ba in start_thread () from /lib/libpthread.so.0
#5  0x00007f10abd58fcd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f10b21b7750 (LWP 3938)):
[KCrash Handler]
#5  0x00007f10abca5fb5 in raise () from /lib/libc.so.6
#6  0x00007f10abca7bc3 in abort () from /lib/libc.so.6
#7  0x00007f10abc9ef09 in __assert_fail () from /lib/libc.so.6
#8  0x00007f1099cd5484 in KMKernel::self () from /usr/lib/libkmailprivate.so.4
#9  0x00007f1099d9ecee in kmcrashHandler () from /usr/lib/libkmailprivate.so.4
#10 0x00007f10ae928361 in KCrash::defaultCrashHandler () from
/usr/lib/libkdeui.so.5
#11 <signal handler called>
#12 0x00007f10b0f67bab in Kontact::Plugin::icon () from
/usr/lib/libkontactinterfaces.so.4
#13 0x00007f10b11958e6 in ?? () from /usr/lib/libkontactprivate.so.4
#14 0x00007f10ada27d13 in QSortFilterProxyModel::data () from
/usr/lib/libQtGui.so.4
#15 0x00007f10ada4c565 in QStyledItemDelegate::initStyleOption () from
/usr/lib/libQtGui.so.4
#16 0x00007f10ada4d508 in QStyledItemDelegate::sizeHint () from
/usr/lib/libQtGui.so.4
#17 0x00007f10b1195f49 in ?? () from /usr/lib/libkontactprivate.so.4
#18 0x00007f10ad9c68c1 in ?? () from /usr/lib/libQtGui.so.4
#19 0x00007f10ad9cab34 in QListView::updateGeometries () from
/usr/lib/libQtGui.so.4
#20 0x00007f10ad4de71a in QWidget::event () from /usr/lib/libQtGui.so.4
#21 0x00007f10ad87840b in QFrame::event () from /usr/lib/libQtGui.so.4
#22 0x00007f10ad9ad2bd in QAbstractItemView::viewportEvent () from
/usr/lib/libQtGui.so.4
#23 0x00007f10ac8e3a68 in
QCoreApplicationPrivate::sendThroughObjectEventFilters () from
/usr/lib/libQtCore.so.4
#24 0x00007f10ad48d75c in QApplicationPrivate::notify_helper () from
/usr/lib/libQtGui.so.4
#25 0x00007f10ad49597a in QApplication::notify () from /usr/lib/libQtGui.so.4
#26 0x00007f10ae8c226b in KApplication::notify () from /usr/lib/libkdeui.so.5
#27 0x00007f10ac8e475c in QCoreApplication::notifyInternal () from
/usr/lib/libQtCore.so.4
#28 0x00007f10ad51b44d in QWidgetPrivate::setGeometry_sys () from
/usr/lib/libQtGui.so.4
#29 0x00007f10ad4dd587 in QWidget::setGeometry () from /usr/lib/libQtGui.so.4
#30 0x00007f10ad9094f4 in QAbstractScrollAreaPrivate::layoutChildren () from
/usr/lib/libQtGui.so.4
#31 0x00007f10ad909b06 in QAbstractScrollArea::event () from
/usr/lib/libQtGui.so.4
#32 0x00007f10ad9a6013 in QAbstractItemView::event () from
/usr/lib/libQtGui.so.4
#33 0x00007f10ad48d78d in QApplicationPrivate::notify_helper () from
/usr/lib/libQtGui.so.4
#34 0x00007f10ad49597a in QApplication::notify () from /usr/lib/libQtGui.so.4
#35 0x00007f10ae8c226b in KApplication::notify () from /usr/lib/libkdeui.so.5
#36 0x00007f10ac8e475c in QCoreApplication::notifyInternal () from
/usr/lib/libQtCore.so.4
#37 0x00007f10ad51b44d in QWidgetPrivate::setGeometry_sys () from
/usr/lib/libQtGui.so.4
#38 0x00007f10ad4dd587 in QWidget::setGeometry () from /usr/lib/libQtGui.so.4
#39 0x00007f10ad4bd43c in QWidgetItem::setGeometry () from
/usr/lib/libQtGui.so.4
#40 0x00007f10ad49bbaf in QBoxLayout::setGeometry () from
/usr/lib/libQtGui.so.4
#41 0x00007f10ad4b8777 in QLayoutPrivate::doResize () from
/usr/lib/libQtGui.so.4
#42 0x00007f10ad48d74e in QApplicationPrivate::notify_helper () from
/usr/lib/libQtGui.so.4
#43 0x00007f10ad49597a in QApplication::notify () from /usr/lib/libQtGui.so.4
#44 0x00007f10ae8c226b in KApplication::notify () from /usr/lib/libkdeui.so.5
#45 0x00007f10ac8e475c in QCoreApplication::notifyInternal () from
/usr/lib/libQtCore.so.4
#46 0x00007f10ad51b44d in QWidgetPrivate::setGeometry_sys () from
/usr/lib/libQtGui.so.4
#47 0x00007f10ad4dd587 in QWidget::setGeometry () from /usr/lib/libQtGui.so.4
#48 0x00007f10ad8d99c9 in ?? () from /usr/lib/libQtGui.so.4
#49 0x00007f10ad8db94c in ?? () from /usr/lib/libQtGui.so.4
#50 0x00007f10ad4de71a in QWidget::event () from /usr/lib/libQtGui.so.4
#51 0x00007f10ad48d78d in QApplicationPrivate::notify_helper () from
/usr/lib/libQtGui.so.4
#52 0x00007f10ad49597a in QApplication::notify () from /usr/lib/libQtGui.so.4
#53 0x00007f10ae8c226b in KApplication::notify () from /usr/lib/libkdeui.so.5
#54 0x00007f10ac8e475c in QCoreApplication::notifyInternal () from
/usr/lib/libQtCore.so.4
#55 0x00007f10ad51b44d in QWidgetPrivate::setGeometry_sys () from
/usr/lib/libQtGui.so.4
#56 0x00007f10ad4dd587 in QWidget::setGeometry () from /usr/lib/libQtGui.so.4
#57 0x00007f10ad4bd43c in QWidgetItem::setGeometry () from
/usr/lib/libQtGui.so.4
#58 0x00007f10ad49bbaf in QBoxLayout::setGeometry () from
/usr/lib/libQtGui.so.4
#59 0x00007f10ad4b8777 in QLayoutPrivate::doResize () from
/usr/lib/libQtGui.so.4
#60 0x00007f10ad48d74e in QApplicationPrivate::notify_helper () from
/usr/lib/libQtGui.so.4
#61 0x00007f10ad49597a in QApplication::notify () from /usr/lib/libQtGui.so.4
#62 0x00007f10ae8c226b in KApplication::notify () from /usr/lib/libkdeui.so.5
#63 0x00007f10ac8e475c in QCoreApplication::notifyInternal () from
/usr/lib/libQtCore.so.4
#64 0x00007f10ad51b44d in QWidgetPrivate::setGeometry_sys () from
/usr/lib/libQtGui.so.4
#65 0x00007f10ad4dd587 in QWidget::setGeometry () from /usr/lib/libQtGui.so.4
#66 0x00007f10ad91db3a in ?? () from /usr/lib/libQtGui.so.4
#67 0x00007f10ad86db0b in ?? () from /usr/lib/libQtGui.so.4
#68 0x00007f10ad896676 in ?? () from /usr/lib/libQtGui.so.4
#69 0x00007f10ad896e75 in ?? () from /usr/lib/libQtGui.so.4
#70 0x00007f10ad4b8777 in QLayoutPrivate::doResize () from
/usr/lib/libQtGui.so.4
#71 0x00007f10ad4b88ce in QLayout::activate () from /usr/lib/libQtGui.so.4
#72 0x00007f10ad4e3f6b in QWidget::setVisible () from /usr/lib/libQtGui.so.4
#73 0x00007f10ad8dfba5 in QStatusBar::insertPermanentWidget () from
/usr/lib/libQtGui.so.4
#74 0x00007f10ae9ae2b2 in KStatusBar::insertItem () from /usr/lib/libkdeui.so.5
#75 0x00007f109c3119c3 in KABCore::slotContactsUpdated () from
/usr/lib/libkaddressbookprivate.so.4
#76 0x00007f109c31a33d in KABCore::qt_metacall () from
/usr/lib/libkaddressbookprivate.so.4
#77 0x00007f10ac8fa1f2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#78 0x00007f109c34ee2b in ?? () from /usr/lib/libkaddressbookprivate.so.4
#79 0x00007f109c30f2e5 in KABCore::save () from
/usr/lib/libkaddressbookprivate.so.4
#80 0x00007f108da4c70d in ?? () from /usr/lib/kde4/kaddressbookpart.so
#81 0x00007f10b0f684ae in Kontact::Plugin::~Plugin () from
/usr/lib/libkontactinterfaces.so.4
#82 0x00007f109b78bdf5 in ?? () from
/usr/lib/kde4/kontact_kaddressbookplugin.so
#83 0x00007f10b118b10e in Kontact::MainWindow::~MainWindow () from
/usr/lib/libkontactprivate.so.4
#84 0x0000000000404a5e in _start ()

*** Bug 205103 has been marked as a duplicate of this bug. ***

*** Bug 208103 has been marked as a duplicate of this bug. ***

*** Bug 211486 has been marked as a duplicate of this bug. ***

No duplicate with recent kdepim version. Closing as worksforme. Feel free to reopen this report if you're able to reproduce this crash in kdepim >= 4.7.1