Version:            (using KDE Devel)
Installed from:    Compiled sources
Compiler:          gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r3, propolice) 
OS:          Linux

KMail crashed on me when I 

- accidentally deleted some messages by 
  holding down the delete key for too long
- hit Ctrl-Z several times to undo this 
- tried to delete a message again after having read it
  (AFAICT that's what triggered the crash)

It's been in a local folder. 
Unfortunately I couldn't reproduce it.

Here's the backtrace: 

[New Thread 16384 (LWP 3341)]
0x41eff137 in waitpid () from /lib/libpthread.so.0
#0  0x41eff137 in waitpid () from /lib/libpthread.so.0
#1  0x412c1d9d in KCrash::defaultCrashHandler(int) ()
   from /usr/local/kde/lib/libkdecore.so.4
#2  0x41efdfea in __pthread_sighandler () from /lib/libpthread.so.0
#3  <signal handler called>
#4  0x40273df1 in QValueListPrivate<unsigned long>::QValueListPrivate(QValueListPrivate<unsigned long> const&) () from /usr/local/kde/lib/libkmailprivate.so.0
#5  0x40273d9d in QValueList<unsigned long>::detachInternal() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#6  0x4027351b in KMail::UndoStack::addMsgToAction(int, unsigned long) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#7  0x40304051 in KMMoveCommand::execute() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#8  0x402fc1b5 in KMCommand::slotPostTransfer(bool) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#9  0x402f6733 in KMCommand::qt_invoke(int, QUObject*) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#10 0x402fa81d in KMMenuCommand::qt_invoke(int, QUObject*) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#11 0x402fac94 in KMMoveCommand::qt_invoke(int, QUObject*) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#12 0x402faf0d in KMDeleteMsgCommand::qt_invoke(int, QUObject*) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#13 0x417169bd in QObject::activate_signal(QConnectionList*, QUObject*) (
    this=0x84ce730, clist=0x835f170, o=0xbfffe6f0) at kernel/qobject.cpp:2333
#14 0x41717302 in QObject::activate_signal_bool(int, bool) (this=0x84ce730, 
    signal=2, param=true) at kernel/qobject.cpp:2429
#15 0x402f665a in KMCommand::messagesTransfered(bool) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#16 0x402fc1f3 in KMCommand::transferSelectedMsgs() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#17 0x402fc021 in KMCommand::preTransfer() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#18 0x402fbe1f in KMCommand::start() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#19 0x401adf54 in KMHeaders::deleteMsg() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#20 0x403161cb in KMMainWidget::slotTrashMsg() ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#21 0x4030f18d in KMMainWidget::qt_invoke(int, QUObject*) ()
   from /usr/local/kde/lib/libkmailprivate.so.0
#22 0x417169bd in QObject::activate_signal(QConnectionList*, QUObject*) (
    this=0x823c3c0, clist=0x823c748, o=0xbfffe9b0) at kernel/qobject.cpp:2333
#23 0x4171685d in QObject::activate_signal(int) (this=0x823c3c0, signal=2)
    at kernel/qobject.cpp:2302
#24 0x41001c9b in KAction::activated() () from /usr/local/kde/lib/libkdeui.so.4
#25 0x4100164f in KAction::slotActivated() ()
   from /usr/local/kde/lib/libkdeui.so.4
#26 0x41001ea1 in KAction::qt_invoke(int, QUObject*) ()
   from /usr/local/kde/lib/libkdeui.so.4
#27 0x417169bd in QObject::activate_signal(QConnectionList*, QUObject*) (
    this=0x829b6a8, clist=0x838cee8, o=0xbfffeab0) at kernel/qobject.cpp:2333
#28 0x4171685d in QObject::activate_signal(int) (this=0x829b6a8, signal=2)
    at kernel/qobject.cpp:2302
#29 0x412b91db in KAccelPrivate::menuItemActivated() ()
   from /usr/local/kde/lib/libkdecore.so.4
#30 0x412b7a11 in KAccelPrivate::eventFilter(QObject*, QEvent*) ()
   from /usr/local/kde/lib/libkdecore.so.4
#31 0x4171445b in QObject::activate_filters(QEvent*) (this=0x805b908, 
    e=0xbfffee90) at kernel/qobject.cpp:902
#32 0x417142d9 in QObject::event(QEvent*) (this=0x805b908, e=0xbfffee90)
    at kernel/qobject.cpp:735
#33 0x4174e305 in QWidget::event(QEvent*) (this=0x805b908, e=0xbfffee90)
    at kernel/qwidget.cpp:4408
#34 0x41815456 in QMainWindow::event(QEvent*) (this=0x805b908, e=0xbfffee90)
    at widgets/qmainwindow.cpp:1669
#35 0x416b3b77 in QApplication::internalNotify(QObject*, QEvent*) (
    this=0xbffff3a0, receiver=0x805b908, e=0xbfffee90)
    at kernel/qapplication.cpp:2582
#36 0x416b3207 in QApplication::notify(QObject*, QEvent*) (this=0xbffff3a0, 
    receiver=0x81dbde8, e=0xbfffee90) at kernel/qapplication.cpp:2339
#37 0x41232d6c in KApplication::notify(QObject*, QEvent*) ()
   from /usr/local/kde/lib/libkdecore.so.4
#38 0x412b6a4b in KAccelEventHandler::x11Event(_XEvent*) ()
   from /usr/local/kde/lib/libkdecore.so.4
#39 0x412382c2 in KApplication::x11EventFilter(_XEvent*) ()
   from /usr/local/kde/lib/libkdecore.so.4
#40 0x41637b1b in qt_x11EventFilter (ev=0xbffff1d0)
    at kernel/qapplication_x11.cpp:378
#41 0x41640c81 in QApplication::x11ProcessEvent(_XEvent*) (this=0xbffff3a0, 
    event=0xbffff1d0) at kernel/qapplication_x11.cpp:3274
#42 0x4165b43d in QEventLoop::processEvents(unsigned) (this=0x80d4618, flags=4)
    at kernel/qeventloop_x11.cpp:192
#43 0x416c988d in QEventLoop::enterLoop() (this=0x80d4618)
    at kernel/qeventloop.cpp:198
#44 0x416c97a6 in QEventLoop::exec() (this=0x80d4618)
    at kernel/qeventloop.cpp:145
#45 0x416b3ce7 in QApplication::exec() (this=0xbffff3a0)
    at kernel/qapplication.cpp:2705
#46 0x0804b752 in main ()
#47 0x4205790c in __libc_start_main () from /lib/libc.so.6