Version:           4.3.0-0ubuntu1~jaunty1~ppa2 (using KDE 4.2.4)
OS:                Linux
Installed from:    Ubuntu Packages

I'm not sure what triggered this crash exactly.  The reporting assistant thinks it's helpful, though, so here it is :)  kio-http doesn't launch anymore, so I had to enter it manually.

I think it is because I am on Ubuntu Jaunty, had the kubuntu-ppa backports repository in my sources, and it recommended upgrading kontact from 4.2.4 to 4.3.  I don't think it upgraded the rest of KDE, though, so that is probably the cause, not an actual bug.  Here's the report anyway in case I'm mistaken:

Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#5  QHash<QObject*, QString>::findNode (this=0x313acc8, akey=<value optimized out>, ahp=0x0) at ../../include/QtCore/../../src/corelib/tools/qhash.h:857
#6  0x00007f5abcb754f4 in QSignalMapper::map (this=0x2524e88, sender=0x36c0660) at ../../include/QtCore/../../src/corelib/tools/qhash.h:847
#7  0x00007f5abcb760d0 in QSignalMapper::qt_metacall (this=0x2524e88, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffca614100) at .moc/release-shared/moc_qsignalmapper.cpp:81
#8  0x00007f5abcb71ea2 in QMetaObject::activate (sender=0x36c0660, from_signal_index=<value optimized out>, to_signal_index=30, argv=0x1) at kernel/qobject.cpp:3113
#9  0x00007f5abdcfce27 in QAbstractButton::clicked (this=0x313acc8, _t1=false) at .moc/release-shared/moc_qabstractbutton.cpp:200
#10 0x00007f5abda56c6b in QAbstractButtonPrivate::emitClicked (this=0x371a7f0) at widgets/qabstractbutton.cpp:543
#11 0x00007f5abda588c2 in QAbstractButtonPrivate::click (this=0x371a7f0) at widgets/qabstractbutton.cpp:536
#12 0x00007f5abda58b15 in QAbstractButton::mouseReleaseEvent (this=0x36c0660, e=0x7fffca6148d0) at widgets/qabstractbutton.cpp:1115
#13 0x00007f5abd72c0bf in QWidget::event (this=0x36c0660, event=0x7fffca6148d0) at kernel/qwidget.cpp:7549
#14 0x00007f5abd6daf4d in QApplicationPrivate::notify_helper (this=0xb8dd00, receiver=0x36c0660, e=0x7fffca6148d0) at kernel/qapplication.cpp:4056
#15 0x00007f5abd6e38ea in QApplication::notify (this=<value optimized out>, receiver=0x36c0660, e=0x7fffca6148d0) at kernel/qapplication.cpp:3758
#16 0x00007f5abeadf71b in KApplication::notify (this=0x7fffca616820, receiver=0x36c0660, event=0x7fffca6148d0) at /build/buildd/kde4libs-4.3.0/kdeui/kernel/kapplication.cpp:302
#17 0x00007f5abcb5c6ac in QCoreApplication::notifyInternal (this=0x7fffca616820, receiver=0x36c0660, event=0x7fffca6148d0) at kernel/qcoreapplication.cpp:610
#18 0x00007f5abd6e2b38 in QApplicationPrivate::sendMouseEvent (receiver=0x36c0660, event=0x7fffca6148d0, alienWidget=0x36c0660, nativeWidget=0x3e0a2d0, buttonDown=<value optimized out>, 
    lastMouseReceiver=@0x7f5abe112010) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#19 0x00007f5abd74cb19 in QETWidget::translateMouseEvent (this=0x3e0a2d0, event=<value optimized out>) at kernel/qapplication_x11.cpp:4409
#20 0x00007f5abd74bb53 in QApplication::x11ProcessEvent (this=0x7fffca616820, event=0x7fffca616450) at kernel/qapplication_x11.cpp:3550
#21 0x00007f5abd774454 in x11EventSourceDispatch (s=0xb72ba0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#22 0x00007f5ab62ad20a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#23 0x00007f5ab62b08e0 in ?? () from /usr/lib/libglib-2.0.so.0
#24 0x00007f5ab62b0a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#25 0x00007f5abcb85a8f in QEventDispatcherGlib::processEvents (this=0xb480a0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#26 0x00007f5abd773bdf in QGuiEventDispatcherGlib::processEvents (this=0x313acc8, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#27 0x00007f5abcb5af42 in QEventLoop::processEvents (this=<value optimized out>, flags={i = -899586240}) at kernel/qeventloop.cpp:149
#28 0x00007f5abcb5b314 in QEventLoop::exec (this=0x7fffca616780, flags={i = -899586160}) at kernel/qeventloop.cpp:201
#29 0x00007f5abcb5d5e4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#30 0x0000000000404945 in _start ()