Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.3
Operating System: Linux 2.6.30-ARCH x86_64

What I was doing when the application crashed:
When I added the unit converter to the desktop and tried clicking the dropdown menu widget for it, plasma crashed. I can't seem to reproduce the crash, but hopefully the backtrace might help.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 1547)]

Thread 2 (Thread 0x7f53c8beb910 (LWP 1549)):
#0  0x00007f53e804fdd9 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007f53e82bac2b in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#2  0x00007f53e473bc9c in ?? () from /usr/lib/libQtNetwork.so.4
#3  0x00007f53e82b9b65 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007f53e804b57a in start_thread () from /lib/libpthread.so.0
#5  0x00007f53e5a1714d in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f53e887d750 (LWP 1547)):
[KCrash Handler]
#5  0x00007f53e66b9dc4 in QGraphicsItem::isWidget () from /usr/lib/libQtGui.so.4
#6  0x00007f53e66bc4f9 in QGraphicsItem::isWindow () from /usr/lib/libQtGui.so.4
#7  0x00007f53e66efc49 in QGraphicsScene::event () from /usr/lib/libQtGui.so.4
#8  0x00007f53e613c07c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#9  0x00007f53e614334e in QApplication::notify () from /usr/lib/libQtGui.so.4
#10 0x00007f53e6d6f8d6 in KApplication::notify () from /usr/lib/libkdeui.so.5
#11 0x00007f53e839ebbc in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#12 0x00007f53e67013f6 in QGraphicsView::viewportEvent () from /usr/lib/libQtGui.so.4
#13 0x00007f53e839df07 in QCoreApplicationPrivate::sendThroughObjectEventFilters () from /usr/lib/libQtCore.so.4
#14 0x00007f53e613c04c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#15 0x00007f53e614334e in QApplication::notify () from /usr/lib/libQtGui.so.4
#16 0x00007f53e6d6f8d6 in KApplication::notify () from /usr/lib/libkdeui.so.5
#17 0x00007f53e839ebbc in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#18 0x00007f53e618ac7b in QWidget::event () from /usr/lib/libQtGui.so.4
#19 0x00007f53e64e3d26 in QFrame::event () from /usr/lib/libQtGui.so.4
#20 0x00007f53e6572a59 in QAbstractScrollArea::event () from /usr/lib/libQtGui.so.4
#21 0x00007f53e613c07c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#22 0x00007f53e614334e in QApplication::notify () from /usr/lib/libQtGui.so.4
#23 0x00007f53e6d6f8d6 in KApplication::notify () from /usr/lib/libkdeui.so.5
#24 0x00007f53e839ebbc in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#25 0x00007f53e61466db in QApplication::setActiveWindow () from /usr/lib/libQtGui.so.4
#26 0x00007f53e61a7bbe in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#27 0x00007f53e61cf96c in ?? () from /usr/lib/libQtGui.so.4
#28 0x00007f53e50a1dbe in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#29 0x00007f53e50a5568 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#30 0x00007f53e50a5690 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#31 0x00007f53e83c70d6 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#32 0x00007f53e61cf14e in ?? () from /usr/lib/libQtGui.so.4
#33 0x00007f53e839d4f2 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#34 0x00007f53e839d8c4 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#35 0x00007f53e839fa79 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#36 0x00007f53dc52a28f in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#37 0x0000000000406eae in _start ()

Reported using DrKonqi