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 2.6.31-20-generic x86_64
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
When adding the class to a package  and clicking apply the application segfaults occasionllay

 -- Backtrace:
Application: Modelador de UML Umbrello (umbrello), signal: Segmentation fault
[KCrash Handler]
#5  0x0000000200000001 in ?? ()
#6  0x0000000000c0f1fa in ?? ()
#7  0x00007f06c68d410b in Q3ScrollView::viewportMouseDoubleClickEvent (this=0x23a9d00, e=0x7fffdc244830) at widgets/q3scrollview.cpp:1776
#8  0x00007f06c68d591e in Q3ScrollView::eventFilter (this=0x23a9d00, obj=0x23a9bc0, e=0x7fffdc244830) at widgets/q3scrollview.cpp:1484
#9  0x00007f06c687b4d6 in Q3ListView::eventFilter (this=0x23a9d00, o=0x23a9bc0, e=0x7fffdc244830) at itemviews/q3listview.cpp:3787
#10 0x00007f06c6da5f47 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x23a9bc0, event=0x7fffdc244830) at kernel/qcoreapplication.cpp:726
#11 0x00007f06c76c6ecc in QApplicationPrivate::notify_helper (this=0x1ee07a0, receiver=0x23a9bc0, e=0x7fffdc244830) at kernel/qapplication.cpp:4052
#12 0x00007f06c76ce011 in QApplication::notify (this=<value optimized out>, receiver=0x23a9bc0, e=0x7fffdc244830) at kernel/qapplication.cpp:3758
#13 0x00007f06c879cab6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#14 0x00007f06c6da6c2c in QCoreApplication::notifyInternal (this=0x7fffdc246750, receiver=0x23a9bc0, event=0x7fffdc244830) at kernel/qcoreapplication.cpp:610
#15 0x00007f06c76cd8e0 in QCoreApplication::sendSpontaneousEvent (receiver=0x23a9bc0, event=0x7fffdc244830, alienWidget=0x23a9bc0, nativeWidget=0x20e79b0, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#16 QApplicationPrivate::sendMouseEvent (receiver=0x23a9bc0, event=0x7fffdc244830, alienWidget=0x23a9bc0, nativeWidget=0x20e79b0, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at kernel/qapplication.cpp:2924
#17 0x00007f06c7733a0e in QETWidget::translateMouseEvent (this=0x20e79b0, event=<value optimized out>) at kernel/qapplication_x11.cpp:4409
#18 0x00007f06c7732aa9 in QApplication::x11ProcessEvent (this=<value optimized out>, event=0x7fffdc246360) at kernel/qapplication_x11.cpp:3550
#19 0x00007f06c775bd0c in x11EventSourceDispatch (s=<value optimized out>, callback=<value optimized out>, user_data=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:146
#20 0x00007f06c280bb1a in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#21 0x00007f06c280f4a8 in ?? () from /lib/libglib-2.0.so.0
#22 0x00007f06c280f66c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#23 0x00007f06c6dcf1a6 in QEventDispatcherGlib::processEvents (this=0x1eb9f00, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#24 0x00007f06c775b4be in QGuiEventDispatcherGlib::processEvents (this=0x23ff690, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#25 0x00007f06c6da5532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#26 0x00007f06c6da5904 in QEventLoop::exec (this=0x7fffdc246690, flags=) at kernel/qeventloop.cpp:201
#27 0x00007f06c6da7ab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#28 0x0000000000bbe3e5 in ?? ()
#29 0x00007f06c5c60abd in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, 
    rtld_fini=<value optimized out>, stack_end=0x7fffdc246bd8) at libc-start.c:220
#30 0x0000000000436599 in _start ()

Reported using DrKonqi