Application: words (2.4 Alpha 1)
KDE Platform Version: 4.5.86 (4.6 >= 20101210) (Compiled from sources)
Qt Version: 4.7.1
Operating System: Linux 2.6.36-gentoo-r5 x86_64

-- Information about the crash:
Testcase:
Start Words and create a blank document.
Type one line and add a page break (Control + Enter)
Type another line
Trigger undo (Control + Z) many times

The crash can be reproduced every time.

-- Backtrace:
Application: Words (words), signal: Segmentation fault
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib64/gcc/x86_64-pc-linux-gnu/4.5.2/libstdc++.so.6.0.14-gdb.py", line 59, in <module>
    from libstdcxx.v6.printers import register_libstdcxx_printers
ImportError: No module named libstdcxx.v6.printers
[Current thread is 1 (Thread 0x7f52465337a0 (LWP 2120))]

Thread 4 (Thread 0x7f522a645710 (LWP 2121)):
#0  0x00007f5240b125c3 in poll () from /lib/libc.so.6
#1  0x00007f523bbc8482 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f523bbc87fb in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007f52418f3386 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#4  0x00007f52418c69a2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#5  0x00007f52418c6d8d in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#6  0x00007f52417d5c8d in QThread::exec() () from /usr/lib64/qt4/libQtCore.so.4
#7  0x00007f52418a6f48 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#8  0x00007f52417d8bbe in ?? () from /usr/lib64/qt4/libQtCore.so.4
#9  0x00007f523f639ae3 in ?? () from //usr/lib64/opengl/nvidia/lib/libGL.so.1
#10 0x00007f5241548894 in start_thread () from /lib/libpthread.so.0
#11 0x00007f5240b1b27d in clone () from /lib/libc.so.6

Thread 3 (Thread 0x7f5228110710 (LWP 2124)):
#0  0xffffffffff600177 in ?? ()
#1  0x00007fff0bbff6cd in ?? ()
#2  0x00007f523a3f2318 in clock_gettime () from /lib/librt.so.1
#3  0x00007f524182c424 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#4  0x00007f52418f530d in ?? () from /usr/lib64/qt4/libQtCore.so.4
#5  0x00007f52418f5335 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#6  0x00007f52418f356d in ?? () from /usr/lib64/qt4/libQtCore.so.4
#7  0x00007f52418f360d in ?? () from /usr/lib64/qt4/libQtCore.so.4
#8  0x00007f523bbc7eef in g_main_context_prepare () from /usr/lib/libglib-2.0.so.0
#9  0x00007f523bbc82ad in ?? () from /usr/lib/libglib-2.0.so.0
#10 0x00007f523bbc87fb in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#11 0x00007f52418f3386 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#12 0x00007f52418c69a2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#13 0x00007f52418c6d8d in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#14 0x00007f52417d5c8d in QThread::exec() () from /usr/lib64/qt4/libQtCore.so.4
#15 0x00007f52418a6f48 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#16 0x00007f52417d8bbe in ?? () from /usr/lib64/qt4/libQtCore.so.4
#17 0x00007f523f639ae3 in ?? () from //usr/lib64/opengl/nvidia/lib/libGL.so.1
#18 0x00007f5241548894 in start_thread () from /lib/libpthread.so.0
#19 0x00007f5240b1b27d in clone () from /lib/libc.so.6

Thread 2 (Thread 0x7f5227907710 (LWP 2129)):
#0  0x00007f5240b149e3 in select () from /lib/libc.so.6
#1  0x00007f52418a483b in ?? () from /usr/lib64/qt4/libQtCore.so.4
#2  0x00007f52417d8bbe in ?? () from /usr/lib64/qt4/libQtCore.so.4
#3  0x00007f523f639ae3 in ?? () from //usr/lib64/opengl/nvidia/lib/libGL.so.1
#4  0x00007f5241548894 in start_thread () from /lib/libpthread.so.0
#5  0x00007f5240b1b27d in clone () from /lib/libc.so.6

Thread 1 (Thread 0x7f52465337a0 (LWP 2120)):
[KCrash Handler]
#6  KoShape::absoluteTransformation (this=0x0, converter=0x0) at /home/kde/src/KDE/calligra/libs/flake/KoShape.cpp:385
#7  0x00007f522ea594f8 in TextShape::convertScreenPos (this=0x0, point=...) at /home/kde/src/KDE/calligra/plugins/textshape/TextShape.cpp:195
#8  0x00007f522ea60a7b in TextTool::pointToPosition (this=0x15e0140, point=<value optimized out>) at /home/kde/src/KDE/calligra/plugins/textshape/TextTool.cpp:912
#9  0x00007f522ea67dcc in TextTool::mouseMoveEvent (this=0x15e0140, event=0x7fff0bb17560) at /home/kde/src/KDE/calligra/plugins/textshape/TextTool.cpp:954
#10 0x00007f524559e53b in KoToolProxy::mouseMoveEvent (this=0x14a6b70, event=0x7fff0bb180d0, point=<value optimized out>) at /home/kde/src/KDE/calligra/libs/flake/KoToolProxy.cpp:249
#11 0x00007f52315e613d in KWCanvas::mouseMoveEvent (this=0x14a2880, e=0x7fff0bb180d0) at /home/kde/src/KDE/calligra/words/part/KWCanvas.cpp:85
#12 0x00007f5242ae2ae7 in QWidget::event(QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#13 0x00007f5242a8d40c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#14 0x00007f5242a9522e in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#15 0x00007f52437dab66 in KApplication::notify(QObject*, QEvent*) () from /home/kde/KDE/lib/libkdeui.so.5
#16 0x00007f52418c7c1b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#17 0x00007f5242a917c5 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib64/qt4/libQtGui.so.4
#18 0x00007f5242b14cf3 in ?? () from /usr/lib64/qt4/libQtGui.so.4
#19 0x00007f5242b13d99 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#20 0x00007f5242b3dad2 in ?? () from /usr/lib64/qt4/libQtGui.so.4
#21 0x00007f523bbc499c in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#22 0x00007f523bbc8570 in ?? () from /usr/lib/libglib-2.0.so.0
#23 0x00007f523bbc87fb in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#24 0x00007f52418f3333 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#25 0x00007f5242b3d44e in ?? () from /usr/lib64/qt4/libQtGui.so.4
#26 0x00007f52418c69a2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#27 0x00007f52418c6d8d in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#28 0x00007f52418cbc21 in QCoreApplication::exec() () from /usr/lib64/qt4/libQtCore.so.4
#29 0x00007f52461611d3 in kdemain (argc=<value optimized out>, argv=<value optimized out>) at /home/kde/src/KDE/calligra/words/part/main.cpp:38
#30 0x00007f5240a68bbd in __libc_start_main () from /lib/libc.so.6
#31 0x0000000000400849 in _start ()

Reported using DrKonqi