Application that crashed: kontact
Version of the application: 4.3.2
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-17-generic x86_64
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
kontact starts two times, if I close one kontact-window the other crash (kmail is loaded)

maybe plasma?

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
The current source language is "auto; currently c".
[KCrash Handler]
#5  0x00007f2c411b1875 in KMMainWidget::slotCheckMail (this=<value optimized out>) at ../../kmail/kmmainwidget.cpp:1045
#6  0x00007f2c411d46cd in KMMainWidget::qt_metacall (this=0xee0b60, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff84a4e540) at ./kmmainwidget.moc:355
#7  0x00007f2c56563ddc in QMetaObject::activate (sender=0x27f8a80, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x7fff84a4e540) at kernel/qobject.cpp:3113
#8  0x00007f2c56e690a7 in QAction::triggered (this=0xee0b60, _t1=false) at .moc/release-shared/moc_qaction.cpp:236
#9  0x00007f2c56e6a4ef in QAction::activate (this=0x27f8a80, event=<value optimized out>) at kernel/qaction.cpp:1160
#10 0x00007f2c571d3fea in QAbstractButtonPrivate::click (this=0x3aade60) at widgets/qabstractbutton.cpp:525
#11 0x00007f2c571d4275 in QAbstractButton::mouseReleaseEvent (this=0x3a91110, e=0x7fff84a4ec70) at widgets/qabstractbutton.cpp:1115
#12 0x00007f2c572a2cba in QToolButton::mouseReleaseEvent (this=0xee0b60, e=0x0) at widgets/qtoolbutton.cpp:709
#13 0x00007f2c56ebd9c0 in QWidget::event (this=0x3a91110, event=0x7fff84a4ec70) at kernel/qwidget.cpp:7549
#14 0x00007f2c56e6eefc in QApplicationPrivate::notify_helper (this=0xd09b70, receiver=0x3a91110, e=0x7fff84a4ec70) at kernel/qapplication.cpp:4056
#15 0x00007f2c56e76011 in QApplication::notify (this=<value optimized out>, receiver=0x3a91110, e=0x7fff84a4ec70) at kernel/qapplication.cpp:3758
#16 0x00007f2c57aa5ab6 in KApplication::notify (this=0x7fff84a50b90, receiver=0x3a91110, event=0x7fff84a4ec70) at ../../kdeui/kernel/kapplication.cpp:302
#17 0x00007f2c5654ec2c in QCoreApplication::notifyInternal (this=0x7fff84a50b90, receiver=0x3a91110, event=0x7fff84a4ec70) at kernel/qcoreapplication.cpp:610
#18 0x00007f2c56e758e0 in QCoreApplication::sendSpontaneousEvent (receiver=0x3a91110, event=0x7fff84a4ec70, alienWidget=0x3a91110, nativeWidget=0xddd230, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#19 QApplicationPrivate::sendMouseEvent (receiver=0x3a91110, event=0x7fff84a4ec70, alienWidget=0x3a91110, nativeWidget=0xddd230, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at kernel/qapplication.cpp:2924
#20 0x00007f2c56edba0e in QETWidget::translateMouseEvent (this=0xddd230, event=<value optimized out>) at kernel/qapplication_x11.cpp:4409
#21 0x00007f2c56edaaa9 in QApplication::x11ProcessEvent (this=<value optimized out>, event=0x7fff84a507a0) at kernel/qapplication_x11.cpp:3550
#22 0x00007f2c56f03d0c in x11EventSourceDispatch (s=<value optimized out>, callback=<value optimized out>, user_data=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:146
#23 0x00007f2c4fdc8bce in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#24 0x00007f2c4fdcc598 in ?? () from /lib/libglib-2.0.so.0
#25 0x00007f2c4fdcc6c0 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#26 0x00007f2c565771a6 in QEventDispatcherGlib::processEvents (this=0xcd5cb0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#27 0x00007f2c56f034be in QGuiEventDispatcherGlib::processEvents (this=0xee0b60, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#28 0x00007f2c5654d532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#29 0x00007f2c5654d904 in QEventLoop::exec (this=0x7fff84a50ad0, flags=) at kernel/qeventloop.cpp:201
#30 0x00007f2c5654fab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#31 0x0000000000403f47 in main (argc=<value optimized out>, argv=<value optimized out>) at ../../../kontact/src/main.cpp:218

Reported using DrKonqi