Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.00 (KDE 4.3.0)
Qt Version: 4.5.2
Operating System: Linux 2.6.28-15-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
add panel to the left, set auto hide, add widgets, try drag widgets in the new panel, ooops! 
btw, the new report assistant is good!

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 3603)]

Thread 4 (Thread 0x7f05544fb950 (LWP 3604)):
#0  0x00007f056e3e62e9 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007f05724e9d19 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#2  0x00007f057137381c in ?? () from /usr/lib/libQtNetwork.so.4
#3  0x00007f05724e8d35 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007f056e3e23ba in start_thread () from /lib/libpthread.so.0
#5  0x00007f056efc6fcd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7f0551682950 (LWP 3831)):
#0  0x00007f056e3e656d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007f0548217f91 in ?? () from /usr/lib/libxine.so.1
#2  0x00007f056e3e23ba in start_thread () from /lib/libpthread.so.0
#3  0x00007f056efc6fcd in clone () from /lib/libc.so.6
#4  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f0542a95950 (LWP 3832)):
#0  0x00007f056efbd496 in poll () from /lib/libc.so.6
#1  0x00007f056e63477f in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f056e634a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007f05725fbaae in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#4  0x00007f05725d0f42 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#5  0x00007f05725d1314 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#6  0x00007f05724e5dc8 in QThread::exec () from /usr/lib/libQtCore.so.4
#7  0x00007f054847362c in ?? () from /usr/lib/kde4/plugins/phonon_backend/phonon_xine.so
#8  0x00007f05724e8d35 in ?? () from /usr/lib/libQtCore.so.4
#9  0x00007f056e3e23ba in start_thread () from /lib/libpthread.so.0
#10 0x00007f056efc6fcd in clone () from /lib/libc.so.6
#11 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f0572ab1750 (LWP 3603)):
[KCrash Handler]
#5  0x00007f057013cad4 in QGraphicsItem::isWidget () from /usr/lib/libQtGui.so.4
#6  0x00007f057013f279 in QGraphicsItem::isWindow () from /usr/lib/libQtGui.so.4
#7  0x00007f0570175df1 in QGraphicsScene::event () from /usr/lib/libQtGui.so.4
#8  0x00007f056fb9df4d in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#9  0x00007f056fba618a in QApplication::notify () from /usr/lib/libQtGui.so.4
#10 0x00007f0570cb071b in KApplication::notify () from /usr/lib/libkdeui.so.5
#11 0x00007f05725d26ac in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#12 0x00007f05701863d6 in QGraphicsView::viewportEvent () from /usr/lib/libQtGui.so.4
#13 0x00007f05725d19b8 in QCoreApplicationPrivate::sendThroughObjectEventFilters () from /usr/lib/libQtCore.so.4
#14 0x00007f056fb9df1c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#15 0x00007f056fba618a in QApplication::notify () from /usr/lib/libQtGui.so.4
#16 0x00007f0570cb071b in KApplication::notify () from /usr/lib/libkdeui.so.5
#17 0x00007f05725d26ac in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#18 0x00007f056fbef22a in QWidget::event () from /usr/lib/libQtGui.so.4
#19 0x00007f056ff61f0b in QFrame::event () from /usr/lib/libQtGui.so.4
#20 0x00007f056fff3639 in QAbstractScrollArea::event () from /usr/lib/libQtGui.so.4
#21 0x00007f056fb9df4d in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#22 0x00007f056fba618a in QApplication::notify () from /usr/lib/libQtGui.so.4
#23 0x00007f0570cb071b in KApplication::notify () from /usr/lib/libkdeui.so.5
#24 0x00007f05725d26ac in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#25 0x00007f056fba4cb8 in QApplication::setActiveWindow () from /usr/lib/libQtGui.so.4
#26 0x00007f056fc0e5c0 in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#27 0x00007f056fc37454 in ?? () from /usr/lib/libQtGui.so.4
#28 0x00007f056e63120a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#29 0x00007f056e6348e0 in ?? () from /usr/lib/libglib-2.0.so.0
#30 0x00007f056e634a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#31 0x00007f05725fba8f in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#32 0x00007f056fc36bdf in ?? () from /usr/lib/libQtGui.so.4
#33 0x00007f05725d0f42 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#34 0x00007f05725d1314 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#35 0x00007f05725d35e4 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#36 0x00007f056720c1eb in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#37 0x0000000000407215 in _start ()

Reported using DrKonqi