If you can reproduce the crash at will, may you read http://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports and post a complete backtrace here? 
You need to install the "kdepim-dbg" package.
Thanks

Here is the complet backtrace.

Uygulama: Kontact (kontact), sinyal SIGSEGV
[Current thread is 0 (LWP 4513)]

Thread 2 (Thread 0xb058ab90 (LWP 4552)):
#0  0xb7f65424 in __kernel_vsyscall ()
#1  0xb6a986c1 in select () from /lib/i686/cmov/libc.so.6
#2  0xb7728920 in QProcessManager::run (this=0x9e38b78) at io/qprocess_unix.cpp:305
#3  0xb765780e in QThreadPrivate::start (arg=0x9e38b78) at thread/qthread_unix.cpp:189
#4  0xb51804e5 in start_thread () from /lib/i686/cmov/libpthread.so.0
#5  0xb6aa021e in clone () from /lib/i686/cmov/libc.so.6

Thread 1 (Thread 0xb4821930 (LWP 4513)):
[KCrash Handler]
#6  QTextCodec::fromUnicode (this=0x0, str=@0xbfc8076c) at codecs/qtextcodec.cpp:1189
#7  0xb10c90e5 in KMMessage::setBodyFromUnicode (this=0xa99b7a8, str=@0xbfc8076c, entity=0x0) at ../../kmail/kmmessage.cpp:4222
#8  0xb14ba10e in KMail::TemplateParser::addProcessedBodyToMessage (this=0xbfc8081c, body=@0xbfc8076c) at ../../kmail/templateparser.cpp:891
#9  0xb14bb2bd in KMail::TemplateParser::processWithTemplate (this=0xbfc8081c, tmpl=@0xbfc807c8) at ../../kmail/templateparser.cpp:856
#10 0xb14ba29d in KMail::TemplateParser::process (this=0xbfc8081c, aorig_msg=0x0, afolder=0xa29a138, append=false) at ../../kmail/templateparser.cpp:194
#11 0xb12d9779 in KMKernel::newMessage (this=0xa1d1268, to=@0xaf01de0, cc=@0xb0858f0, bcc=@0xa751338, hidden=false, useFolderId=true, _attachURL=@0xaecf970) at ../../kmail/kmkernel.cpp:649
#12 0xb1568dae in KmailAdaptor::newMessage (this=0xa237d20, to=@0xaf01de0, cc=@0xb0858f0, bcc=@0xa751338, hidden=<value optimized out>, useFolderId=<value optimized out>, messageFile=@0xa6da330, 
    attachURL=@0xaecf970) at kmailadaptor.cpp:135
#13 0xb1569715 in KmailAdaptor::qt_metacall (this=0xa237d20, _c=QMetaObject::InvokeMetaMethod, _id=17, _a=0xbfc809d8) at kmailadaptor.moc:254
#14 0xb6024ec5 in QDBusConnectionPrivate::deliverCall (this=0x9e2e628, object=0xa237d20, msg=@0xbfc80e38, metaTypes=@0xbfc80b18, slotIdx=21) at qdbusintegrator.cpp:891
#15 0xb6026052 in QDBusConnectionPrivate::activateCall (this=0x9e2e628, object=0xa237d20, flags=273, msg=@0xbfc80e38) at qdbusintegrator.cpp:796
#16 0xb60265c1 in QDBusConnectionPrivate::activateObject (this=0x9e2e628, node=@0xbfc80c80, msg=@0xbfc80e38, pathStartPos=6) at qdbusintegrator.cpp:1375
#17 0xb6027137 in QDBusConnectionPrivate::handleObjectCall (this=0x9e2e628, msg=@0xbfc80e38) at qdbusintegrator.cpp:1448
#18 0xb602775a in QDBusConnectionPrivate::handleMessage (this=0x9e2e628, amsg=@0xbfc80e38) at qdbusintegrator.cpp:535
#19 0xb6027a19 in QDBusConnectionPrivate::sendWithReplyLocal (this=0x9e2e628, message=@0xbfc81078) at qdbusintegrator.cpp:1802
#20 0xb6029fa5 in QDBusConnectionPrivate::sendWithReply (this=0x9e2e628, message=@0xbfc81078, sendMode=1, timeout=-1) at qdbusintegrator.cpp:1748
#21 0xb6013491 in QDBusConnection::call (this=0xa166e0c, message=@0xbfc81078, mode=QDBus::Block, timeout=-1) at qdbusconnection.cpp:516
#22 0xb6031c1b in QDBusAbstractInterface::callWithArgumentList (this=0xa6b9008, mode=QDBus::Block, method=@0xbfc81154, args=@0xbfc81158) at qdbusabstractinterface.cpp:402
#23 0xb1896291 in OrgKdeKmailKmailInterface::newMessage (this=0xa6b9008, to=@0xbfc81200, cc=@0xbfc811c0, bcc=@0xbfc811bc, hidden=false, useFolderId=true, messageFile=@0xbfc811c8, 
    attachURL=@0xbfc811c4) at kmailinterface.h:148
#24 0xb1893633 in KMailPlugin::openComposer (this=0xa142d20, to=@0xbfc81200) at ../../../../kontact/plugins/kmail/kmail_plugin.cpp:130
#25 0xb1893763 in KMailPlugin::slotNewMail (this=0xa142d20) at ../../../../kontact/plugins/kmail/kmail_plugin.cpp:136
#26 0xb189380b in KMailPlugin::qt_metacall (this=0xa142d20, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfc8131c) at ./kmail_plugin.moc:68
#27 0xb7760b98 in QMetaObject::activate (sender=0xa152280, from_signal_index=5, to_signal_index=6, argv=0xbfc8131c) at kernel/qobject.cpp:3120
#28 0xb7760fd0 in QMetaObject::activate (sender=0xa152280, m=0xb75e06c8, from_local_signal_index=1, to_local_signal_index=2, argv=0xbfc8131c) at kernel/qobject.cpp:3214
#29 0xb6d4b141 in QAction::triggered (this=0xa152280, _t1=false) at .moc/release-shared/moc_qaction.cpp:236
#30 0xb6d4c6bf in QAction::activate (this=0xa152280, event=QAction::Trigger) at kernel/qaction.cpp:1160
#31 0xb7f31ab3 in Kontact::MainWindow::slotNewClicked (this=0x9e4a118) at /usr/include/qt4/QtGui/qaction.h:195
#32 0xb7f3b0f8 in Kontact::MainWindow::qt_metacall (this=0x9e4a118, _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbfc8148c) at ./mainwindow.moc:114
#33 0xb7760b98 in QMetaObject::activate (sender=0xa084370, from_signal_index=5, to_signal_index=6, argv=0xbfc8148c) at kernel/qobject.cpp:3120
#34 0xb7760fd0 in QMetaObject::activate (sender=0xa084370, m=0xb75e06c8, from_local_signal_index=1, to_local_signal_index=2, argv=0xbfc8148c) at kernel/qobject.cpp:3214
#35 0xb6d4b141 in QAction::triggered (this=0xa084370, _t1=false) at .moc/release-shared/moc_qaction.cpp:236
#36 0xb6d4c6bf in QAction::activate (this=0xa084370, event=QAction::Trigger) at kernel/qaction.cpp:1160
#37 0xb721bd72 in QToolButton::nextCheckState (this=0x804d9d0) at ../../include/QtGui/../../src/gui/kernel/qaction.h:203
#38 0xb71346a3 in QAbstractButtonPrivate::click (this=0xa1394f8) at widgets/qabstractbutton.cpp:525
#39 0xb7134976 in QAbstractButton::mouseReleaseEvent (this=0x9f72d00, e=0xbfc81b5c) at widgets/qabstractbutton.cpp:1115
#40 0xb721c26c in QToolButton::mouseReleaseEvent (this=0x9f72d00, e=0xbfc81b5c) at widgets/qtoolbutton.cpp:709
#41 0xb6da83b3 in QWidget::event (this=0x9f72d00, event=0xbfc81b5c) at kernel/qwidget.cpp:7521
#42 0xb713291e in QAbstractButton::event (this=0x9f72d00, e=0xbfc81b5c) at widgets/qabstractbutton.cpp:1077
#43 0xb721ec9a in QToolButton::event (this=0x9f72d00, event=0xbfc81b5c) at widgets/qtoolbutton.cpp:1151
#44 0xb6d517bc in QApplicationPrivate::notify_helper (this=0x9e36750, receiver=0x9f72d00, e=0xbfc81b5c) at kernel/qapplication.cpp:4057
#45 0xb6d5a441 in QApplication::notify (this=0xbfc834fc, receiver=0x9f72d00, e=0xbfc81b5c) at kernel/qapplication.cpp:3759
#46 0xb7c38b7d in KApplication::notify (this=0xbfc834fc, receiver=0x9f72d00, event=0xbfc81b5c) at ../../kdeui/kernel/kapplication.cpp:307
#47 0xb774aa2b in QCoreApplication::notifyInternal (this=0xbfc834fc, receiver=0x9f72d00, event=0xbfc81b5c) at kernel/qcoreapplication.cpp:610
#48 0xb6d594ae in QApplicationPrivate::sendMouseEvent (receiver=0x9f72d00, event=0xbfc81b5c, alienWidget=0x9f72d00, nativeWidget=0xa13bd88, buttonDown=0xb75fe9e0, lastMouseReceiver=@0xb75fe9e4)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#49 0xb6dc8dc5 in QETWidget::translateMouseEvent (this=0xa13bd88, event=0xbfc8310c) at kernel/qapplication_x11.cpp:4448
#50 0xb6dc8266 in QApplication::x11ProcessEvent (this=0xbfc834fc, event=0xbfc8310c) at kernel/qapplication_x11.cpp:3444
#51 0xb6df29a2 in x11EventSourceDispatch (s=0x9e38a80, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#52 0xb51cc848 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#53 0xb51cfdab in ?? () from /usr/lib/libglib-2.0.so.0
#54 0x09e38870 in ?? ()
#55 0x00000000 in ?? ()

Thanks!. Marking as duplicate of bug 154373.

*** This bug has been marked as a duplicate of bug 154373 ***