Version:           1.3.9 (using KDE KDE 3.5.2)
Installed from:    Gentoo Packages
Compiler:          gcc 4.1.1 
OS:                Linux

Kalarm always crashes for me when the following sequence of actions is performed: 
1. create a new alarm. The alarm is without any recurrence, the action is command 
   (tried "xmms -p" and "xterm"). An alarm in one minute will show the problem
2. Shortly before the alarm fires, select the alarm and press Delete key. 
3. A "Do you really want to delete the selected alarm" dialog box will show up.
4. Alarm time comes and alarm fires. In my case xmms or xterm is launched.
5. Hit delete on the dialog box. 
6. Kalarm will crash.
The problem seems to occur every time I find myself having ran the scenario.

Stack trace as displayed by the KDE crash handler:
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Using host libthread_db library "/lib/libthread_db.so.1".
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`system-supplied DSO at 0xffffe000' has disappeared; keeping its symbols.
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[Thread debugging using libthread_db enabled]
[New Thread -1243703632 (LWP 29637)]
[KCrash handler]
#6  0xb6b16766 in QFont::operator= () from /usr/qt/3/lib/libqt-mt.so.3
#7  0x08082b13 in QValueListPrivate<KCal::Person>::~QValueListPrivate ()
#8  0x080c8722 in KMainWindow::metaObject ()
#9  0x080ca17e in KMainWindow::metaObject ()
#10 0xb6b594b9 in QObject::activate_signal () from /usr/qt/3/lib/libqt-mt.so.3
#11 0xb6b5a10d in QObject::activate_signal () from /usr/qt/3/lib/libqt-mt.so.3
#12 0xb7420619 in KAction::activated () from /usr/kde/3.5/lib/libkdeui.so.4
#13 0xb7420671 in KAction::slotActivated () from /usr/kde/3.5/lib/libkdeui.so.4
#14 0xb742373f in KAction::qt_invoke () from /usr/kde/3.5/lib/libkdeui.so.4
#15 0xb6b594b9 in QObject::activate_signal () from /usr/qt/3/lib/libqt-mt.so.3
#16 0xb6b5a10d in QObject::activate_signal () from /usr/qt/3/lib/libqt-mt.so.3
#17 0xb71dc289 in KAccelPrivate::menuItemActivated ()
   from /usr/kde/3.5/lib/libkdecore.so.4
#18 0xb71dcde7 in KAccelPrivate::emitActivatedSignal ()
   from /usr/kde/3.5/lib/libkdecore.so.4
#19 0xb71dd27c in KAccelPrivate::eventFilter ()
   from /usr/kde/3.5/lib/libkdecore.so.4
#20 0xb6b58db6 in QObject::activate_filters () from /usr/qt/3/lib/libqt-mt.so.3
#21 0xb6b58e1b in QObject::event () from /usr/qt/3/lib/libqt-mt.so.3
#22 0xb6b91eac in QWidget::event () from /usr/qt/3/lib/libqt-mt.so.3
#23 0xb6c4ca22 in QMainWindow::event () from /usr/qt/3/lib/libqt-mt.so.3
#24 0xb6afa3d7 in QApplication::internalNotify ()
   from /usr/qt/3/lib/libqt-mt.so.3
#25 0xb6afb5d8 in QApplication::notify () from /usr/qt/3/lib/libqt-mt.so.3
#26 0xb7155e5e in KApplication::notify () from /usr/kde/3.5/lib/libkdecore.so.4
#27 0xb71de159 in KAccelEventHandler::x11Event ()
   from /usr/kde/3.5/lib/libkdecore.so.4
#28 0xb715c0d3 in KApplication::x11EventFilter ()
   from /usr/kde/3.5/lib/libkdecore.so.4
#29 0xb6a89dc4 in qt_set_x11_event_filter () from /usr/qt/3/lib/libqt-mt.so.3
#30 0x08186ff8 in ?? ()
#31 0xbfb4d858 in ?? ()
#32 0x00000001 in ?? ()
#33 0xb6fb9608 in ?? () from /usr/qt/3/lib/libqt-mt.so.3
#34 0xb6fb9608 in ?? () from /usr/qt/3/lib/libqt-mt.so.3
#35 0x0000006b in ?? ()
#36 0xbfb4d748 in ?? ()
#37 0xb6a99718 in QApplication::x11ProcessEvent ()
   from /usr/qt/3/lib/libqt-mt.so.3
#38 0xb6a99718 in QApplication::x11ProcessEvent ()
   from /usr/qt/3/lib/libqt-mt.so.3
#39 0xb6aaa551 in QEventLoop::processEvents () from /usr/qt/3/lib/libqt-mt.so.3
#40 0xb6b10f01 in QEventLoop::enterLoop () from /usr/qt/3/lib/libqt-mt.so.3
#41 0xb6b10d86 in QEventLoop::exec () from /usr/qt/3/lib/libqt-mt.so.3
#42 0xb6af9e5f in QApplication::exec () from /usr/qt/3/lib/libqt-mt.so.3
#43 0x0807ce49 in QValueListPrivate<KCal::Person>::~QValueListPrivate ()
#44 0xb5e04878 in __libc_start_main () from /lib/libc.so.6
#45 0x08077171 in ?? ()