Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.5.3
Operating System: Linux 2.6.31-bfs i686

What I was doing when the application crashed:
My  config: kde4.3.4 on Arch + kdemod. 
Plasma-desktop crashed at the instant I plugged back my laptop, going from battery to electric cable.
I'm not sure, but the bug may be related to energy profiles. I have 2 energy profile (that I used today):
- "Powersave" that is my default profile, with compositing enabled.
-"Extreme powersave" without compositing
(-> I modified some of the settings for those profile from their defaults)
Before unplugging the laptop I switched from "Powersave" to "Extreme Powersave" using the battery monitor plasmoid. Then I unplugged, but this automatically returns me to the "Powersave" profile which is my normal profile when the battery is full. So I switched it again to  "Extreme Powersave". I used my computer like that for a while. Coming back to my desk I plugged it back. Then the crash occured. The compositing was active just after the crash (I could use the kwin effects).
I was not able to reproduce the bug.

 -- Backtrace:
Application: Espace de travail Plasma (plasma-desktop), signal: Segmentation fault
[KCrash Handler]
#6  0xb7451e0a in Plasma::Svg::paint(QPainter*, QRectF const&, QString const&) () from /usr/lib/libplasma.so.3
#7  0xa8a5f32b in NetworkManagerApplet::paintInterface(QPainter*, QStyleOptionGraphicsItem const*, QRect const&) () from /usr/lib/kde4/plasma_applet_networkmanagement.so
#8  0xb73d1668 in Plasma::Applet::paint(QPainter*, QStyleOptionGraphicsItem const*, QWidget*) () from /usr/lib/libplasma.so.3
#9  0xb681fd93 in _q_paintItem (item=<value optimized out>, painter=<value optimized out>, option=0xbfea5558, widget=0x0, useWindowOpacity=false, painterStateProtection=true)
    at graphicsview/qgraphicsscene.cpp:4630
#10 0xb682008a in _q_paintIntoCache (pix=<value optimized out>, item=<value optimized out>, pixmapExposed=..., itemToPixmap=..., renderHints=..., option=0xbfea5558, 
    painterStateProtection=<value optimized out>) at graphicsview/qgraphicsscene.cpp:4668
#11 0xb682cb7a in QGraphicsScenePrivate::drawItemHelper (this=0x9fdb678, item=0xa2dc5d8, painter=0xbfea60f8, option=0xa3bb170, widget=0xa1b0d70, painterStateProtection=true)
    at graphicsview/qgraphicsscene.cpp:4953
#12 0xb682d3ef in QGraphicsScene::drawItems (this=0xa0072a0, painter=0xbfea60f8, numItems=9, items=0xa0b39d8, options=0xa3bae58, widget=0xa1b0d70) at graphicsview/qgraphicsscene.cpp:5102
#13 0xb683af8c in QGraphicsView::drawItems (this=0xa2a1678, painter=0xbfea60f8, numItems=9, items=0xa0b39d8, options=0xa3bae58) at graphicsview/qgraphicsview.cpp:3777
#14 0xb6847cce in QGraphicsView::paintEvent (this=0xa2a1678, event=0xbfea66e4) at graphicsview/qgraphicsview.cpp:3528
#15 0xb76d612c in PanelView::paintEvent(QPaintEvent*) () from /usr/lib/libkdeinit4_plasma-desktop.so
#16 0xb6257f94 in QWidget::event (this=0xa2a1678, event=0xbfea66e4) at kernel/qwidget.cpp:7692
#17 0xb65fe253 in QFrame::event (this=0xa2a1678, e=0xbfea66e4) at widgets/qframe.cpp:559
#18 0xb669b9d4 in QAbstractScrollArea::viewportEvent (this=0xe, e=0x74006b) at widgets/qabstractscrollarea.cpp:962
#19 0xb684560f in QGraphicsView::viewportEvent (this=0xa2a1678, event=0xbfea66e4) at graphicsview/qgraphicsview.cpp:2919
#20 0xb669dfc5 in QAbstractScrollAreaPrivate::viewportEvent (this=0xa23ab58, o=0xa1b0d70, e=0xbfea66e4) at widgets/qabstractscrollarea_p.h:100
#21 QAbstractScrollAreaFilter::eventFilter (this=0xa23ab58, o=0xa1b0d70, e=0xbfea66e4) at widgets/qabstractscrollarea_p.h:111
#22 0xb5f7f76a in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x9f35670, receiver=0xa1b0d70, event=0xbfea66e4) at kernel/qcoreapplication.cpp:726
#23 0xb62038fc in QApplicationPrivate::notify_helper (this=0x9f35670, receiver=0xa1b0d70, e=0xbfea66e4) at kernel/qapplication.cpp:4061
#24 0xb620af5a in QApplication::notify (this=0x9f2eb88, receiver=0xa1b0d70, e=0xbfea66e4) at kernel/qapplication.cpp:4030
#25 0xb6ec760a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#26 0xb5f805bb in QCoreApplication::notifyInternal (this=0x9f2eb88, receiver=0xa1b0d70, event=0xbfea66e4) at kernel/qcoreapplication.cpp:610
#27 0xb625ffa5 in QCoreApplication::sendSpontaneousEvent (this=0x9f34328, pdev=0xa2a870c, rgn=..., offset=..., flags=<value optimized out>, sharedPainter=0x0, backingStore=0xa26aee0)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#28 QWidgetPrivate::drawWidget (this=0x9f34328, pdev=0xa2a870c, rgn=..., offset=..., flags=<value optimized out>, sharedPainter=0x0, backingStore=0xa26aee0) at kernel/qwidget.cpp:5084
#29 0xb62607a1 in QWidgetPrivate::paintSiblingsRecursive (this=0xa2ec6d0, pdev=0xa2a870c, siblings=..., index=3, rgn=..., offset=..., flags=4, sharedPainter=0x0, backingStore=0xa26aee0)
    at kernel/qwidget.cpp:5194
#30 0xb625fb96 in QWidgetPrivate::drawWidget (this=0xa2ec6d0, pdev=0xa2a870c, rgn=..., offset=..., flags=<value optimized out>, sharedPainter=0x0, backingStore=0xa26aee0) at kernel/qwidget.cpp:5133
#31 0xb63e7773 in QWidgetBackingStore::sync (this=0xa26aee0) at painting/qbackingstore.cpp:1272
#32 0xb63e7bba in QWidgetBackingStore::sync (this=0xa26aee0, exposedWidget=0xa2a1678, exposedRegion=...) at painting/qbackingstore.cpp:1077
#33 0xb6251395 in QWidgetPrivate::syncBackingStore (this=0xa2ec6d0, region=...) at kernel/qwidget.cpp:1612
#34 0xb6269110 in QETWidget::translatePaintEvent (this=0xa2a1678, event=0xbfea8260) at kernel/qapplication_x11.cpp:5111
#35 0xb627743a in QApplication::x11ProcessEvent (this=0x9f2eb88, event=0xbfea8260) at kernel/qapplication_x11.cpp:3452
#36 0xb62a1fd2 in x11EventSourceDispatch (s=0x9f383b0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#37 0xb4605328 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#38 0xb4608ba0 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#39 0xb4608cd3 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#40 0xb5faad25 in QEventDispatcherGlib::processEvents (this=0x9f002d8, flags=...) at kernel/qeventdispatcher_glib.cpp:407
#41 0xb62a1705 in QGuiEventDispatcherGlib::processEvents (this=0x9f002d8, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#42 0xb5f7eba9 in QEventLoop::processEvents (this=0xbfea8554, flags=) at kernel/qeventloop.cpp:149
#43 0xb5f7effa in QEventLoop::exec (this=0xbfea8554, flags=...) at kernel/qeventloop.cpp:201
#44 0xb5f8146f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#45 0xb62037a7 in QApplication::exec () at kernel/qapplication.cpp:3525
#46 0xb76ccb7d in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#47 0x080485ab in _start ()

Reported using DrKonqi