Version:           1.9.4 (using KDE KDE 3.5.4)
Installed from:    FreeBSD Ports
Compiler:          gcc (GCC) 3.4.6 [FreeBSD] 20060305 
OS:                FreeBSD

How to reproduce this bug:

1- do a search for messages in local folders, try something that will generate 40 or more results;
2- select the "Last Search" folder;
3- select all messages in the "Last Search" folder;
4- drag them to another folder

At this point, KMail crashes. Here's my backtrace:

[New Thread 0x82e3400 (sleeping)]
[New Thread 0x82e3200 (sleeping)]
[New Thread 0x82e3000 (sleeping)]
[New Thread 0x82c6e00 (sleeping)]
[New Thread 0x82c6c00 (LWP 100084)]
[New Thread 0x8055000 (sleeping)]
[New LWP 100170]
[Switching to LWP 100170]
0x2a3fe4f7 in pthread_testcancel () from /lib/libpthread.so.2
#0  0x2a3fe4f7 in pthread_testcancel () from /lib/libpthread.so.2
#1  0x2a3f780f in pthread_mutexattr_init () from /lib/libpthread.so.2
#2  0x2a3fa70c in pthread_setconcurrency () from /lib/libpthread.so.2
#3  0x2a3f0a3a in _nanosleep () from /lib/libpthread.so.2
#4  0x2a485df9 in sleep () from /lib/libc.so.6
#5  0x2a3e63fe in sleep () from /lib/libpthread.so.2
#6  0x298a3abe in KCrash::startDrKonqi () from /usr/local/lib/libkdecore.so.6
#7  0x298a3e64 in KCrash::defaultCrashHandler ()
   from /usr/local/lib/libkdecore.so.6
#8  0x2a3eba42 in sigaction () from /lib/libpthread.so.2
#9  0x2a3ecee5 in sigaction () from /lib/libpthread.so.2
#10 0x2a3f5d31 in pthread_mutexattr_init () from /lib/libpthread.so.2
#11 0x2a3f5d9f in pthread_mutexattr_init () from /lib/libpthread.so.2
#12 0x2a4ac137 in _ctx_start () from /lib/libc.so.6
#13 0x00000000 in ?? ()
#14 0xbfbfddc0 in ?? ()
#15 0xbfbfdb00 in ?? ()
#16 0x00000000 in ?? ()
#17 0x2a3f5d5c in pthread_mutexattr_init () from /lib/libpthread.so.2
#18 0x283c0c26 in KMMoveCommand::execute ()
   from /usr/local/lib/libkmailprivate.so
#19 0x283b6d6b in KMCommand::slotPostTransfer ()
   from /usr/local/lib/libkmailprivate.so
#20 0x283ba854 in KMCommand::qt_invoke ()
   from /usr/local/lib/libkmailprivate.so
#21 0x283bab11 in KMMenuCommand::qt_invoke ()
   from /usr/local/lib/libkmailprivate.so
#22 0x283be786 in KMMoveCommand::qt_invoke ()
   from /usr/local/lib/libkmailprivate.so
#23 0x29d8b6a8 in QObject::activate_signal ()
   from /usr/X11R6/lib/libqt-mt.so.3
#24 0x283b1a94 in KMCommand::messagesTransfered ()
   from /usr/local/lib/libkmailprivate.so
#25 0x283b544c in KMCommand::transferSelectedMsgs ()
   from /usr/local/lib/libkmailprivate.so
#26 0x283ba4c1 in KMCommand::slotStart ()
   from /usr/local/lib/libkmailprivate.so
#27 0x283ba842 in KMCommand::qt_invoke ()
   from /usr/local/lib/libkmailprivate.so
#28 0x283bab11 in KMMenuCommand::qt_invoke ()
   from /usr/local/lib/libkmailprivate.so
#29 0x283be786 in KMMoveCommand::qt_invoke ()
   from /usr/local/lib/libkmailprivate.so
#30 0x29d8b6a8 in QObject::activate_signal ()
   from /usr/X11R6/lib/libqt-mt.so.3
#31 0x2a08cf53 in QSignal::signal () from /usr/X11R6/lib/libqt-mt.so.3
#32 0x29da27ee in QSignal::activate () from /usr/X11R6/lib/libqt-mt.so.3
#33 0x29da92db in QSingleShotTimer::event () from /usr/X11R6/lib/libqt-mt.so.3
#34 0x29d2f549 in QApplication::internalNotify ()
   from /usr/X11R6/lib/libqt-mt.so.3
#35 0x29d2f6de in QApplication::notify () from /usr/X11R6/lib/libqt-mt.so.3
#36 0x29814112 in KApplication::notify () from /usr/local/lib/libkdecore.so.6
#37 0x29d23cc4 in QEventLoop::activateTimers ()
   from /usr/X11R6/lib/libqt-mt.so.3
#38 0x29ce1b84 in QEventLoop::processEvents ()
   from /usr/X11R6/lib/libqt-mt.so.3
#39 0x29d4393f in QEventLoop::enterLoop () from /usr/X11R6/lib/libqt-mt.so.3
#40 0x29d43898 in QEventLoop::exec () from /usr/X11R6/lib/libqt-mt.so.3
#41 0x29d2e884 in QApplication::exec () from /usr/X11R6/lib/libqt-mt.so.3
#42 0x0804a603 in main ()