Version:           SVN (using KDE KDE 3.5.3)
Installed from:    Ubuntu Packages
Compiler:          gcc-4.0.3 
OS:                Linux

I was trying to close a chat tab clicking on the X button on the top-right corner in the tab-bar, but kopete crashed with this backtrace:

Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread -1240037696 (LWP 5348)]
[New Thread -1282524240 (LWP 5629)]
[KCrash handler]
#6  0xb72d6397 in KXMLGUI::ActionList::unplug () from /usr/lib/libkdeui.so.4
#7  0xb7356514 in KXMLGUI::ContainerNode::unplugClient ()
   from /usr/lib/libkdeui.so.4
#8  0xb735677f in KXMLGUI::ContainerNode::unplugActions ()
   from /usr/lib/libkdeui.so.4
#9  0xb73571bd in KXMLGUI::ContainerNode::destruct ()
   from /usr/lib/libkdeui.so.4
#10 0xb7357374 in KXMLGUI::ContainerNode::destructChildren ()
   from /usr/lib/libkdeui.so.4
#11 0xb73571ab in KXMLGUI::ContainerNode::destruct ()
   from /usr/lib/libkdeui.so.4
#12 0xb7357374 in KXMLGUI::ContainerNode::destructChildren ()
   from /usr/lib/libkdeui.so.4
#13 0xb73571ab in KXMLGUI::ContainerNode::destruct ()
   from /usr/lib/libkdeui.so.4
#14 0xb7357374 in KXMLGUI::ContainerNode::destructChildren ()
   from /usr/lib/libkdeui.so.4
#15 0xb73571ab in KXMLGUI::ContainerNode::destruct ()
   from /usr/lib/libkdeui.so.4
#16 0xb73d924d in KXMLGUIFactory::removeClient () from /usr/lib/libkdeui.so.4
#17 0xb73d95fa in KXMLGUIFactory::removeClient () from /usr/lib/libkdeui.so.4
#18 0xb5dab066 in KopeteChatWindow::setActiveView (this=0x89b9f08, 
    widget=0x8c714c8)
    at /home/federico/programmi/kopetesvn/0.12/kopete/kopete/chatwindow/kopetechatwindow.cpp:843
#19 0xb5dac036 in KopeteChatWindow::qt_invoke (this=0x89b9f08, _id=77, 
    _o=0xbfd772d8) at kopetechatwindow.moc:242
#20 0xb6974eb9 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#21 0xb6d2a28c in QTabWidget::currentChanged () from /usr/lib/libqt-mt.so.3
#22 0xb6ac4d0f in QTabWidget::showTab () from /usr/lib/libqt-mt.so.3
#23 0xb6d2a42a in QTabWidget::qt_invoke () from /usr/lib/libqt-mt.so.3
#24 0xb739a307 in KTabWidget::qt_invoke () from /usr/lib/libkdeui.so.4
#25 0xb6974eb9 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#26 0xb69757c8 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#27 0xb6d29a59 in QTabBar::selected () from /usr/lib/libqt-mt.so.3
#28 0xb6ac1fed in QTabBar::setCurrentTab () from /usr/lib/libqt-mt.so.3
#29 0xb6ac4d64 in QTabWidget::setCurrentPage () from /usr/lib/libqt-mt.so.3
#30 0xb5dab6b5 in KopeteChatWindow::detachChatView (this=0x89b9f08, 
    view=0x8a819b8)
    at /home/federico/programmi/kopetesvn/0.12/kopete/kopete/chatwindow/kopetechatwindow.cpp:744
#31 0xb5d9cfcc in ChatView::closeView (this=0x8a819b8, force=false)
    at /home/federico/programmi/kopetesvn/0.12/kopete/kopete/chatwindow/chatview.cpp:380
#32 0xb5da8011 in KopeteChatWindow::slotChatClosed (this=0x89b9f08)
    at /home/federico/programmi/kopetesvn/0.12/kopete/kopete/chatwindow/kopetechatwindow.cpp:930
#33 0xb5dac3a8 in KopeteChatWindow::qt_invoke (this=0x89b9f08, _id=114, 
    _o=0xbfd7773c) at kopetechatwindow.moc:279
#34 0xb6974eb9 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#35 0xb6975954 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#36 0xb6d10d1f in QButton::clicked () from /usr/lib/libqt-mt.so.3
#37 0xb6a1055e in QButton::mouseReleaseEvent () from /usr/lib/libqt-mt.so.3
#38 0xb69af68d in QWidget::event () from /usr/lib/libqt-mt.so.3
#39 0xb690ae56 in QApplication::internalNotify () from /usr/lib/libqt-mt.so.3
#40 0xb690b3e0 in QApplication::notify () from /usr/lib/libqt-mt.so.3
#41 0xb708de31 in KApplication::notify () from /usr/lib/libkdecore.so.4
#42 0xb689c1c5 in QApplication::sendSpontaneousEvent ()
   from /usr/lib/libqt-mt.so.3
#43 0xb6897873 in QETWidget::translateMouseEvent ()
   from /usr/lib/libqt-mt.so.3
#44 0xb6895d59 in QApplication::x11ProcessEvent () from /usr/lib/libqt-mt.so.3
#45 0xb68af4db in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#46 0xb6923947 in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#47 0xb692386a in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#48 0xb6909965 in QApplication::exec () from /usr/lib/libqt-mt.so.3
#49 0x08073915 in main (argc=1, argv=0xbfd78374)
    at /home/federico/programmi/kopetesvn/0.12/kopete/kopete/main.cpp:107