kubuntu 9.10 x64 on mt3422 laptop
crash reproducible following original poster's steps 

backtrace:

Application: KMail (kmail), signal: Segmentation fault
The current source language is "auto; currently c".
[KCrash Handler]
#5  0x00007fe339047c97 in KMReaderWin::parseMsg (this=0x2633820, aMsg=0x2d2e940) at ../../kmail/kmreaderwin.cpp:1678
#6  0x00007fe339036eda in KMReaderWin::displayMessage (this=0x2633820) at ../../kmail/kmreaderwin.cpp:1605
#7  0x00007fe3390370b4 in KMReaderWin::updateReaderWin (this=0x2633820) at ../../kmail/kmreaderwin.cpp:1545
#8  0x00007fe339041fac in KMReaderWin::setMsg (this=0x2633820, aMsg=0x2d2e940, force=true) at ../../kmail/kmreaderwin.cpp:1347
#9  0x00007fe339042dc4 in KMReaderWin::slotMessageArrived (this=0x2633820, msg=0x2d2e940) at ../../kmail/kmreaderwin.cpp:935
#10 0x00007fe339043164 in KMReaderWin::qt_metacall (this=0x2633820, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff1634f9e0) at ./kmreaderwin.moc:196
#11 0x00007fe337c7dddc in QMetaObject::activate (sender=0x2740820, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x2fa3450) at kernel/qobject.cpp:3113
#12 0x00007fe339230d9f in KMail::FolderJob::messageRetrieved (this=0x2d2e940, _t1=0x2d2e940) at ./folderjob.moc:99
#13 0x00007fe33923cc97 in KMail::ImapJob::slotGetMessageResult (this=0x2740820, job=<value optimized out>) at ../../kmail/imapjob.cpp:460
#14 0x00007fe33924104b in KMail::ImapJob::qt_metacall (this=0x2740820, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff1634fbe0) at ./imapjob.moc:82
#15 0x00007fe337c7dddc in QMetaObject::activate (sender=0x2617490, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x2fa3450) at kernel/qobject.cpp:3113
#16 0x00007fe339906af2 in KJob::result (this=0x2d2e940, _t1=0x2617490) at ./kjob.moc:188
#17 0x00007fe339906e6f in KJob::emitResult (this=0x2617490) at ../../kdecore/jobs/kjob.cpp:304
#18 0x00007fe331a26d93 in KIO::SimpleJob::slotFinished (this=0x2617490) at ../../kio/kio/job.cpp:477
#19 0x00007fe331a27253 in KIO::TransferJob::slotFinished (this=0x2617490) at ../../kio/kio/job.cpp:948
#20 0x00007fe331a25b61 in KIO::TransferJob::qt_metacall (this=0x2617490, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff16350000) at ./jobclasses.moc:343
#21 0x00007fe337c7dddc in QMetaObject::activate (sender=0x2ea3e80, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x2fa3450) at kernel/qobject.cpp:3113
#22 0x00007fe331ae7a81 in KIO::SlaveInterface::dispatch (this=0x2ea3e80, _cmd=104, rawdata=...) at ../../kio/kio/slaveinterface.cpp:175
#23 0x00007fe331ae4333 in KIO::SlaveInterface::dispatch (this=0x2ea3e80) at ../../kio/kio/slaveinterface.cpp:91
#24 0x00007fe331ad714d in KIO::Slave::gotInput (this=0x2ea3e80) at ../../kio/kio/slave.cpp:322
#25 0x00007fe331ad926c in KIO::Slave::qt_metacall (this=0x2ea3e80, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff163503c0) at ./slave.moc:76
#26 0x00007fe337c7dddc in QMetaObject::activate (sender=0x2c8a8d0, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x2fa3450) at kernel/qobject.cpp:3113
#27 0x00007fe3319f3f57 in KIO::ConnectionPrivate::dequeue (this=0x2eb51e0) at ../../kio/kio/connection.cpp:82
#28 0x00007fe3319f407d in KIO::Connection::qt_metacall (this=0x2c8a8d0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x2f8aa30) at ./connection.moc:73
#29 0x00007fe337c780f9 in QObject::event (this=0x2c8a8d0, e=0x2e60fb0) at kernel/qobject.cpp:1111
#30 0x00007fe3380fbefc in QApplicationPrivate::notify_helper (this=0x23d12c0, receiver=0x2c8a8d0, e=0x2e60fb0) at kernel/qapplication.cpp:4056
#31 0x00007fe3381031ce in QApplication::notify (this=0x7fff16350e90, receiver=0x2c8a8d0, e=0x2e60fb0) at kernel/qapplication.cpp:4021
#32 0x00007fe339ebeab6 in KApplication::notify (this=0x7fff16350e90, receiver=0x2c8a8d0, event=0x2e60fb0) at ../../kdeui/kernel/kapplication.cpp:302
#33 0x00007fe337c68c2c in QCoreApplication::notifyInternal (this=0x7fff16350e90, receiver=0x2c8a8d0, event=0x2e60fb0) at kernel/qcoreapplication.cpp:610
#34 0x00007fe337c6980a in QCoreApplication::sendEvent (receiver=0x0, event_type=<value optimized out>, data=0x2381d00) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#35 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0x2381d00) at kernel/qcoreapplication.cpp:1247
#36 0x00007fe337c91533 in QCoreApplication::sendPostedEvents (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#37 postEventSourceDispatch (s=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:210
#38 0x00007fe32ef01bce in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#39 0x00007fe32ef05598 in ?? () from /lib/libglib-2.0.so.0
#40 0x00007fe32ef056c0 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#41 0x00007fe337c911a6 in QEventDispatcherGlib::processEvents (this=0x2381930, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#42 0x00007fe3381904be in QGuiEventDispatcherGlib::processEvents (this=0x2d2e940, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#43 0x00007fe337c67532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#44 0x00007fe337c67904 in QEventLoop::exec (this=0x7fff16350cc0, flags=) at kernel/qeventloop.cpp:201
#45 0x00007fe337c69ab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#46 0x0000000000402fe9 in main (argc=<value optimized out>, argv=<value optimized out>) at ../../kmail/main.cpp:146