Version:           1.11.0 (using KDE 4.2.0)
OS:                Linux
Installed from:    Ubuntu Packages

Kubuntu intrepid 4:4.2.0-0ubuntu1~intrepid~ppa3 from
deb http://ppa.launchpad.net/kubuntu-experimental/ubuntu intrepid main

Can be reproduced by fast clicking on another mail while the mail with the Outlook-meeting-invitation-mail is still being loaded.

#0  0x00007f0795ac182a in KMReaderWin::parseMsg (this=0x27e40f0, aMsg=0x314a6f0) at /build/buildd/kdepim-4.2.0/kmail/kmreaderwin.cpp:1628
#1  0x00007f0795aaf577 in KMReaderWin::displayMessage (this=0x27e40f0) at /build/buildd/kdepim-4.2.0/kmail/kmreaderwin.cpp:1555
#2  0x00007f0795aaf765 in KMReaderWin::updateReaderWin (this=0x27e40f0) at /build/buildd/kdepim-4.2.0/kmail/kmreaderwin.cpp:1495
#3  0x00007f0795abcc35 in KMReaderWin::qt_metacall (this=0x27e40f0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff9ef56400)
    at /build/buildd/kdepim-4.2.0/obj-x86_64-linux-gnu/kmail/kmreaderwin.moc:164
#4  0x00007f07925d1134 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#5  0x00007f07925cba43 in QObject::event () from /usr/lib/libQtCore.so.4
#6  0x00007f0792ce0c3d in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#7  0x00007f0792ce89ba in QApplication::notify () from /usr/lib/libQtGui.so.4
#8  0x00007f07969443eb in KApplication::notify (this=0x7fff9ef56f10, receiver=0x27e4188, event=0x7fff9ef56ab0)
    at /build/buildd/kde4libs-4.2.0/kdeui/kernel/kapplication.cpp:307
#9  0x00007f07925bcd61 in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#10 0x00007f07925e8ab6 in ?? () from /usr/lib/libQtCore.so.4
#11 0x00007f07925e51fd in ?? () from /usr/lib/libQtCore.so.4
#12 0x00007f0789cbbd3b in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#13 0x00007f0789cbf50d in ?? () from /usr/lib/libglib-2.0.so.0
#14 0x00007f0789cbf6cb in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#15 0x00007f07925e515f in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#16 0x00007f0792d72a6f in ?? () from /usr/lib/libQtGui.so.4
#17 0x00007f07925bb682 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#18 0x00007f07925bb80d in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#19 0x00007f07925bdcbd in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#20 0x000000000040309b in main (argc=<value optimized out>, argv=<value optimized out>) at /build/buildd/kdepim-4.2.0/kmail/main.cpp:146

-- 
Johan Thelmén