Version:           1.9.9 (using KDE 3.5.9)
OS:                Linux
Installed from:    Gentoo Packages

When I open KMail and there are new mail messages in my IMAP account, opening one of the new messages sometimes crashes KMail. This bug often shows up when KMail is simultaneously showing another problem which may be related: KMail fails to read the body of some email messages, and sometimes even the header info is not shown. This behaviour is somewhat random. When you display the same message multiple times in a row, sometimes the header is shown, sometimes it isn't. KMail often crashes at some point while browsing mail messages.

The below backtrace was caught when KMail was started, new mail messages were automatically retreived, and the inbox was opened:

[Thread debugging using libthread_db enabled]
[New Thread 0xb4fa06d0 (LWP 18728)]
[New Thread 0xb34f7b90 (LWP 18737)]
[New Thread 0xb3cf8b90 (LWP 18736)]
[New Thread 0xb44f9b90 (LWP 18735)]
[New Thread 0xb4cfab90 (LWP 18734)]
[KCrash handler]
#6  0xb7f09424 in __kernel_vsyscall ()
#7  0xb4fcf101 in raise () from /lib/libc.so.6
#8  0xb4fd08e8 in abort () from /lib/libc.so.6
#9  0xb51bf764 in __gnu_cxx::__verbose_terminate_handler ()
   from /usr/lib/gcc/i686-pc-linux-gnu/4.1.2/libstdc++.so.6
#10 0xb51bd185 in ?? ()
   from /usr/lib/gcc/i686-pc-linux-gnu/4.1.2/libstdc++.so.6
#11 0xb51bd1c2 in std::terminate ()
   from /usr/lib/gcc/i686-pc-linux-gnu/4.1.2/libstdc++.so.6
#12 0xb51bd896 in __cxa_pure_virtual ()
   from /usr/lib/gcc/i686-pc-linux-gnu/4.1.2/libstdc++.so.6
#13 0xb7b9fa57 in KMReaderWin::setMsg (this=0xa0e2090, aMsg=0xa479e48, 
    force=false) at kmreaderwin.cpp:1208
#14 0xb7d0db36 in KMMainWidget::slotMsgSelected (this=0xa1c24b0, 
    msg=0xa479e48) at kmmainwidget.cpp:2111
#15 0xb7d2171e in KMMainWidget::qt_invoke (this=0xa1c24b0, _id=54, 
    _o=0xbfe21708) at kmmainwidget.moc:498
#16 0xb594eff3 in QObject::activate_signal (this=0xa1d5868, clist=0xa0e1d88, 
    o=0xbfe21708) at kernel/qobject.cpp:2359
#17 0xb7b42dcf in KMHeaders::selected (this=0xa1d5868, t0=0xa479e48)
    at kmheaders.moc:260
#18 0xb7b4a264 in KMHeaders::highlightMessage (this=0xa1d5868, lvi=0xa3f40f0, 
    markitread=false) at kmheaders.cpp:2072
#19 0xb7b4c950 in KMHeaders::highlightMessage (this=0xa1d5868, i=0xa3f40f0)
    at kmheaders.cpp:2351
#20 0xb7b522f7 in KMHeaders::qt_invoke (this=0xa1d5868, _id=106, 
    _o=0xbfe21858) at kmheaders.moc:305
#21 0xb594eff3 in QObject::activate_signal (this=0xa1d5868, clist=0xa203328, 
    o=0xbfe21858) at kernel/qobject.cpp:2359
#22 0xb5d68a5c in QListView::currentChanged (this=0xa1d5868, t0=0xa3f40f0)
    at .moc/debug-shared-mt/moc_qlistview.cpp:328
#23 0xb5a677cc in QListView::setCurrentItem (this=0xa1d5868, i=0xa3f40f0)
    at widgets/qlistview.cpp:5480
#24 0xb5a6b70d in QListView::contentsMousePressEventEx (this=0xa1d5868, 
    e=0xbfe21bec) at widgets/qlistview.cpp:4356
#25 0xb5a6be12 in QListView::contentsMousePressEvent (this=0xa1d5868, 
    e=0xbfe21bec) at widgets/qlistview.cpp:4240
#26 0xb64e4862 in KListView::contentsMousePressEvent (this=0xa1d5868, 
    e=0xbfe21bec) at klistview.cpp:805
#27 0xb7b4cbb6 in KMHeaders::contentsMousePressEvent (this=0xa1d5868, 
    e=0xbfe21bec) at kmheaders.cpp:2235
#28 0xb5aa8203 in QScrollView::viewportMousePressEvent (this=0xa1d5868, 
    e=0xbfe221d4) at widgets/qscrollview.cpp:1736
#29 0xb5aa9730 in QScrollView::eventFilter (this=0xa1d5868, obj=0xa1d6520, 
    e=0xbfe221d4) at widgets/qscrollview.cpp:1499
#30 0xb5a6c2c7 in QListView::eventFilter (this=0xa1d5868, o=0xa1d6520, 
    e=0xbfe221d4) at widgets/qlistview.cpp:3870
#31 0xb7b53368 in KMHeaders::eventFilter (this=0xa1d5868, o=0xa1d6520, 
    e=0xbfe221d4) at kmheaders.cpp:250
#32 0xb594e44b in QObject::activate_filters (this=0xa1d6520, e=0xbfe221d4)
    at kernel/qobject.cpp:906
#33 0xb594e4ec in QObject::event (this=0xa1d6520, e=0xbfe221d4)
    at kernel/qobject.cpp:738
#34 0xb598fc22 in QWidget::event (this=0xa1d6520, e=0xbfe221d4)
    at kernel/qwidget.cpp:4662
#35 0xb58daacf in QApplication::internalNotify (this=0xbfe22804, 
    receiver=0xa1d6520, e=0xbfe221d4) at kernel/qapplication.cpp:2638
#36 0xb58dcdcd in QApplication::notify (this=0xbfe22804, receiver=0xa1d6520, 
    e=0xbfe221d4) at kernel/qapplication.cpp:2424
#37 0xb6188baf in KApplication::notify (this=0xbfe22804, receiver=0xa1d6520, 
    event=0xbfe221d4) at kapplication.cpp:550
#38 0xb5864a2d in QApplication::sendSpontaneousEvent (receiver=0xa1d6520, 
    event=0xbfe221d4) at kernel/qapplication.h:502
#39 0xb586368e in QETWidget::translateMouseEvent (this=0xa1d6520, 
    event=0xbfe22678) at kernel/qapplication_x11.cpp:4301
#40 0xb5861824 in QApplication::x11ProcessEvent (this=0xbfe22804, 
    event=0xbfe22678) at kernel/qapplication_x11.cpp:3452
#41 0xb587a49a in QEventLoop::processEvents (this=0xa070600, flags=4)
    at kernel/qeventloop_x11.cpp:195
#42 0xb58f88ed in QEventLoop::enterLoop (this=0xa070600)
    at kernel/qeventloop.cpp:201
#43 0xb58f870e in QEventLoop::exec (this=0xa070600)
    at kernel/qeventloop.cpp:148
#44 0xb58dc793 in QApplication::exec (this=0xbfe22804)
    at kernel/qapplication.cpp:2761
#45 0x0804af2e in main (argc=7, argv=0xbfe22aa4) at main.cpp:110