Version:            (using KDE KDE 3.5.2)
Installed from:    Compiled From Sources
Compiler:          gcc 4.0.2 
OS:                Linux

I selected a few (approx 4 - 6) messages in a maildir folder and clicked on the move-to-trash button, at which point kmail crashed:

(no debugging symbols found)
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(no debugging symbols found)
...
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread -1249712448 (LWP 8004)]
[New Thread -1277490256 (LWP 8010)]
[New Thread -1269097552 (LWP 8009)]
[New Thread -1260704848 (LWP 8008)]
[New Thread -1252312144 (LWP 8007)]
(no debugging symbols found)
...
(no debugging symbols found)
[KCrash handler]
#6  0xb7c886eb in KMHeaders::msgRemoved ()
   from /opt/kde3.5/lib/libkmailprivate.so
#7  0xb7c8dd37 in KMHeaders::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#8  0xb60837a9 in QObject::activate_signal ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#9  0xb7cc120f in KMFolder::msgRemoved ()
   from /opt/kde3.5/lib/libkmailprivate.so
#10 0xb7cc529b in KMFolder::qt_emit () from /opt/kde3.5/lib/libkmailprivate.so
#11 0xb60837eb in QObject::activate_signal ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#12 0xb7ce568f in FolderStorage::msgRemoved ()
   from /opt/kde3.5/lib/libkmailprivate.so
#13 0xb7ce7261 in FolderStorage::take ()
   from /opt/kde3.5/lib/libkmailprivate.so
#14 0xb7da37ec in KMFolderMaildir::take ()
   from /opt/kde3.5/lib/libkmailprivate.so
#15 0xb7cbfe0e in KMFolder::take () from /opt/kde3.5/lib/libkmailprivate.so
#16 0xb7d750fa in KMFolderMbox::addMsg ()
   from /opt/kde3.5/lib/libkmailprivate.so
#17 0xb7ce45fa in FolderStorage::moveMsg ()
   from /opt/kde3.5/lib/libkmailprivate.so
#18 0xb7cbff75 in KMFolder::moveMsg () from /opt/kde3.5/lib/libkmailprivate.so
#19 0xb7e33ca6 in KMMoveCommand::execute ()
   from /opt/kde3.5/lib/libkmailprivate.so
#20 0xb7e25a51 in KMCommand::slotPostTransfer ()
   from /opt/kde3.5/lib/libkmailprivate.so
#21 0xb7e2c954 in KMCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#22 0xb7e2cc4b in KMMenuCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#23 0xb7e2ccd5 in KMMoveCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#24 0xb7e2cd5b in KMDeleteMsgCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#25 0xb60837a9 in QObject::activate_signal ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#26 0xb7e247aa in KMCommand::messagesTransfered ()
   from /opt/kde3.5/lib/libkmailprivate.so
#27 0xb7e2c543 in KMCommand::transferSelectedMsgs ()
   from /opt/kde3.5/lib/libkmailprivate.so
#28 0xb7e2c737 in KMCommand::slotStart ()
   from /opt/kde3.5/lib/libkmailprivate.so
#29 0xb7e2c966 in KMCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#30 0xb7e2cc4b in KMMenuCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#31 0xb7e2ccd5 in KMMoveCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#32 0xb7e2cd5b in KMDeleteMsgCommand::qt_invoke ()
   from /opt/kde3.5/lib/libkmailprivate.so
#33 0xb60837a9 in QObject::activate_signal ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#34 0xb63b394a in QSignal::signal () from /opt/qt-3.3.4/lib/libqt-mt.so.3
#35 0xb609fbcd in QSignal::activate () from /opt/qt-3.3.4/lib/libqt-mt.so.3
#36 0xb60a72f3 in QSingleShotTimer::event ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#37 0xb602606a in QApplication::internalNotify ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#38 0xb60269ff in QApplication::notify () from /opt/qt-3.3.4/lib/libqt-mt.so.3
#39 0xb67408a2 in KApplication::notify () from /opt/kde3.5/lib/libkdecore.so.4
#40 0xb601aded in QEventLoop::activateTimers ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#41 0xb5fd62ae in QEventLoop::processEvents ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#42 0xb603c4ed in QEventLoop::enterLoop ()
   from /opt/qt-3.3.4/lib/libqt-mt.so.3
#43 0xb603c3f6 in QEventLoop::exec () from /opt/qt-3.3.4/lib/libqt-mt.so.3
#44 0xb6025a7f in QApplication::exec () from /opt/qt-3.3.4/lib/libqt-mt.so.3
#45 0x0804a742 in ?? ()
#46 0xbfdf71e8 in ?? ()
#47 0xbfdf73d4 in ?? ()
#48 0x00000000 in ?? ()