Application that crashed: umbrello
Version of the application: 2.3.2
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-22-generic-pae i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
Using Umbrello on GNU! I created a Sequence diagram and then wanted to remove a "synchronous message" so I pressed CTRL Z, bu then it knocked off a class (not sure why because it should have knocked off the synchronous message). So I did a Redo from the edit menu. Umbrello crashed

 -- Backtrace:
Application: Umbrello UML Modeller (umbrello), signal: Segmentation fault
[KCrash Handler]
#6  0x0869a5c9 in ?? ()
#7  0x086514cb in ?? ()
#8  0xb6bf8097 in QUndoStack::undo() () from /usr/lib/libQtGui.so.4
#9  0xb6c0b003 in QUndoStack::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libQtGui.so.4
#10 0xb70fad82 in KUndoStack::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdeui.so.5
#11 0xb612d263 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQtCore.so.4
#12 0xb612d6d8 in QMetaObject::activate(QObject*, QMetaObject const*, int, int, void**) () from /usr/lib/libQtCore.so.4
#13 0xb656d9b1 in QAction::triggered(bool) () from /usr/lib/libQtGui.so.4
#14 0xb656ef32 in QAction::activate(QAction::ActionEvent) () from /usr/lib/libQtGui.so.4
#15 0xb69bc9cc in ?? () from /usr/lib/libQtGui.so.4
#16 0xb69c303b in ?? () from /usr/lib/libQtGui.so.4
#17 0xb69c3bf7 in QMenu::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/libQtGui.so.4
#18 0xb71451c5 in KMenu::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/libkdeui.so.5
#19 0xb65c9012 in QWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#20 0xb69c5e34 in QMenu::event(QEvent*) () from /usr/lib/libQtGui.so.4
#21 0xb6573f54 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#22 0xb657c033 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#23 0xb705abfa in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#24 0xb61176cb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#25 0xb657af6e in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&) () from /usr/lib/libQtGui.so.4
#26 0xb65e9c87 in ?? () from /usr/lib/libQtGui.so.4
#27 0xb65e8c4b in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#28 0xb6615502 in ?? () from /usr/lib/libQtGui.so.4
#29 0xb549de88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#30 0xb54a1730 in ?? () from /lib/libglib-2.0.so.0
#31 0xb54a1863 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#32 0xb614202c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#33 0xb6614be5 in ?? () from /usr/lib/libQtGui.so.4
#34 0xb6115c79 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#35 0xb61160ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#36 0xb611853f in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#37 0xb6573dd7 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#38 0x086ec2b5 in ?? ()
#39 0xb5a8bb56 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#40 0x08073461 in _start ()

Reported using DrKonqi