interesting ... this report is 9 months old, but I just started getting the crash recently - didn't some attempt to fix it make the situation worse, bringing crashes to those lucky who haven't experienced it earlier?

here's my trace, Fedora 12:

Application: KMail (kmail), signal: Segmentation fault
[KCrash Handler]
#6  KIO::Slave::deref (this=0x9cb0628) at /usr/src/debug/kdelibs-4.3.5/kio/kio/slave.cpp:243
#7  0x05b01057 in KIO::Slave::gotInput (this=<value optimized out>) at /usr/src/debug/kdelibs-4.3.5/kio/kio/slave.cpp:336
#8  0x05b031b3 in KIO::Slave::qt_metacall (this=<value optimized out>, _c=<value optimized out>, _id=<value optimized out>, _a=<value optimized out>)
    at /usr/src/debug/kdelibs-4.3.5/i686-redhat-linux-gnu/kio/slave.moc:76
#9  0x04720c0c in QMetaObject::activate (sender=<value optimized out>, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=<value optimized out>)
    at kernel/qobject.cpp:3112
#10 0x04721843 in QMetaObject::activate (sender=<value optimized out>, m=<value optimized out>, local_signal_index=<value optimized out>, argv=<value optimized out>) at kernel/qobject.cpp:3186
#11 0x05a18438 in KIO::Connection::readyRead (this=<value optimized out>) at /usr/src/debug/kdelibs-4.3.5/i686-redhat-linux-gnu/kio/connection.moc:86
#12 0x05a19efe in KIO::ConnectionPrivate::dequeue (this=<value optimized out>) at /usr/src/debug/kdelibs-4.3.5/kio/kio/connection.cpp:82
#13 0x05a1a026 in KIO::Connection::qt_metacall (this=<value optimized out>, _c=<value optimized out>, _id=<value optimized out>, _a=<value optimized out>)
    at /usr/src/debug/kdelibs-4.3.5/i686-redhat-linux-gnu/kio/connection.moc:73
#14 0x047197fc in QMetaCallEvent::placeMetaCall (this=<value optimized out>, object=<value optimized out>) at kernel/qobject.cpp:477
#15 0x0471af96 in QObject::event (this=<value optimized out>, e=<value optimized out>) at kernel/qobject.cpp:1110
#16 0x04caab24 in QApplicationPrivate::notify_helper (this=<value optimized out>, receiver=<value optimized out>, e=<value optimized out>) at kernel/qapplication.cpp:4065
#17 0x04cb2281 in QApplication::notify (this=<value optimized out>, receiver=<value optimized out>, e=<value optimized out>) at kernel/qapplication.cpp:3605
#18 0x0571a8cb in KApplication::notify (this=<value optimized out>, receiver=<value optimized out>, event=<value optimized out>) at /usr/src/debug/kdelibs-4.3.5/kdeui/kernel/kapplication.cpp:302
#19 0x0470ad73 in QCoreApplication::notifyInternal (this=<value optimized out>, receiver=<value optimized out>, event=<value optimized out>) at kernel/qcoreapplication.cpp:610
#20 0x0470b972 in sendEvent (receiver=<value optimized out>, event_type=<value optimized out>, data=<value optimized out>) at kernel/qcoreapplication.h:213
#21 QCoreApplicationPrivate::sendPostedEvents (receiver=<value optimized out>, event_type=<value optimized out>, data=<value optimized out>) at kernel/qcoreapplication.cpp:1247
#22 0x0470bb2e in QCoreApplication::sendPostedEvents (receiver=<value optimized out>, event_type=<value optimized out>) at kernel/qcoreapplication.cpp:1140
#23 0x04735f40 in sendPostedEvents (s=<value optimized out>) at kernel/qcoreapplication.h:218
#24 postEventSourceDispatch (s=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:210
#25 0x014a8f88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#26 0x014ac8b8 in ?? () from /lib/libglib-2.0.so.0
#27 0x014ac9e4 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#28 0x04735b6d in QEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#29 0x04d4a356 in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#30 0x047092aa in QEventLoop::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qeventloop.cpp:149
#31 0x0470970a in QEventLoop::exec (this=<value optimized out>, flags=<value optimized out>) at kernel/qeventloop.cpp:201
#32 0x0470bbf7 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#33 0x04caa9a8 in QApplication::exec () at kernel/qapplication.cpp:3525
#34 0x0804a59e in main (argc=<value optimized out>, argv=<value optimized out>) at /usr/src/debug/kdepim-4.3.5/kmail/main.cpp:146