Version:            (using KDE 4.2.0)
OS:                Linux
Installed from:    SuSE RPMs

I selected a group of messages in an IMAP folder using the threaded view, then deselected a collapsed thread in the middle of the list of previously selected messages. Whilst moving the messages to the Trash folder (also configured as an IMAP folder on the same mail account) KMail crashed, producing the following backtrace...

Application: KMail (kmail), signal SIGSEGV [?1034h[Thread debugging using libthread_db enabled] Thread 1 (Thread 0xb41786d0 (LWP 26877)): [KCrash Handler] #6 KMail::MessageListView::Widget::getSelectionStats (this=0x82c4b70, selectedSernums=@0xbfcc1938, selectedVisibleSernums=@0xbfcc1934, allSelectedBelongToSameThread=0xbfcc193f, includeCollapsedChildren=<value optimized out>) at /usr/src/debug/kdepim-4.2.0/kmail/messagelistview/widget.cpp:579 #7 0xb78760c6 in KMail::MessageListView::Pane::getSelectionStats (this=0x8236f30, selectedSernums=@0xbfcc1938, selectedVisibleSernums=@0xbfcc1934, allSelectedBelongToSameThread=0xbfcc193f, includeCollapsedChildren=<value optimized out>) at /usr/src/debug/kdepim-4.2.0/kmail/messagelistview/pane.cpp:579 #8 0xb7749357 in KMMainWidget::updateMessageActions (this=0x8236c28) at /usr/src/debug/kdepim-4.2.0/kmail/kmmainwidget.cpp:4288 #9 0xb77639b8 in KMMainWidget::qt_metacall (this=0x8236c28, _c=QMetaObject::InvokeMetaMethod, _id=20, _a=0xbfcc1a08) at /usr/src/debug/kdepim-4.2.0/build/kmail/kmmainwidget.moc:363 #10 0xb6cd8740 in QMetaObject::activate () from /usr/lib/libQtCore.so.4 #11 0xb6cd94c2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4 #12 0xb6d13bc7 in QTimer::timeout () from /usr/lib/libQtCore.so.4 #13 0xb6cdf1de in QTimer::timerEvent () from /usr/lib/libQtCore.so.4 #14 0xb6cd31ff in QObject::event () from /usr/lib/libQtCore.so.4 #15 0xb626882c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4 #16 0xb62706ce in QApplication::notify () from /usr/lib/libQtGui.so.4 #17 0xb7ed068d in KApplication::notify () from /usr/lib/libkdeui.so.5 #18 0xb6cc3a71 in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4 #19 0xb6cf1de6 in ?? () from /usr/lib/libQtCore.so.4 #20 0xb6cee2b0 in ?? () from /usr/lib/libQtCore.so.4 #21 0xb48992d9 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0 #22 0xb489c85b in ?? () from /usr/lib/libglib-2.0.so.0 #23 0xb489c9d8 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0 #24 0xb6cee208 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4 #25 0xb63018c5 in ?? () from /usr/lib/libQtGui.so.4 #26 0xb6cc214a in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4 #27 0xb6cc230a in QEventLoop::exec () from /usr/lib/libQtCore.so.4 #28 0xb6cc49a5 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4 #29 0xb62686a7 in QApplication::exec () from /usr/lib/libQtGui.so.4 #30 0x0804a5c0 in main (argc=) at /usr/src/debug/kdepim-4.2.0/kmail/main.cpp:146 

Will try to reproduce it running under valgrind to see what it says...