Application that crashed: kontact
Version of the application: 4.3.3
KDE Version: 4.3.3 (KDE 4.3.3)
Qt Version: 4.6.0
Operating System: Linux 2.6.31-15-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I don't think i could reproduce it. Random kmail crashes on ubuntu karmic koala for few days.

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  QImageData::checkForAlphaPixels (this=0x0) at image/qimage.cpp:273
#7  0x011f2eeb in QX11AlphaDetector::hasAlpha (this=0xbaf0088, img=..., flags=...) at image/qpixmap_x11.cpp:380
#8  QX11AlphaDetector::hasXRenderAndAlpha (this=0xbaf0088, img=..., flags=...) at image/qpixmap_x11.cpp:387
#9  QX11PixmapData::fromImage (this=0xbaf0088, img=..., flags=...) at image/qpixmap_x11.cpp:431
#10 0x011e48e9 in QPixmapData::fromData (this=0xbaf0088, 
    buf=0xbaf9fd0 "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n<!-- Created with Inkscape (http://www.inkscape.org/) -->\n<svg\n   xmlns:svg=\"http://www.w3.org/2000/svg\"\n   xmlns=\"http://www.w3.org/2000/svg\"\n  "..., len=15103, format=0x0, flags=...) at image/qpixmapdata.cpp:106
#11 0x011db79a in QPixmap::loadFromData (this=0xbfcf6834, 
    buf=0xbaf9fd0 "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n<!-- Created with Inkscape (http://www.inkscape.org/) -->\n<svg\n   xmlns:svg=\"http://www.w3.org/2000/svg\"\n   xmlns=\"http://www.w3.org/2000/svg\"\n  "..., len=15103, format=0x0, flags=...) at image/qpixmap.cpp:866
#12 0x0138d91f in QPixmap::loadFromData (this=0x9d20c80, type=2, name=...) at ../../include/QtGui/../../src/gui/image/qpixmap.h:302
#13 QTextDocument::loadResource (this=0x9d20c80, type=2, name=...) at text/qtextdocument.cpp:1929
#14 0x01382939 in QTextDocument::resource (this=0x9d20c80, type=2, name=...) at text/qtextdocument.cpp:1821
#15 0x013cb9d5 in getPixmap (doc=<value optimized out>, format=...) at text/qtextimagehandler.cpp:67
#16 0x013ccd89 in getPixmapSize (this=0xaeb7e80, doc=0x9d20c80, posInDocument=105, format=...) at text/qtextimagehandler.cpp:108
#17 QTextImageHandler::intrinsicSize (this=0xaeb7e80, doc=0x9d20c80, posInDocument=105, format=...) at text/qtextimagehandler.cpp:217
#18 0x013adbe3 in QTextDocumentLayout::resizeInlineObject (this=0xb2c9bf8, item=..., posInDocument=105, format=...) at text/qtextdocumentlayout.cpp:2961
#19 0x01367a8e in QTextEngine::shape (this=0xbaf02c8, item=0) at text/qtextengine.cpp:1350
#20 0x0136e6ea in QTextLine::layout_helper (this=0xbfcf6f20, maxGlyphs=2147483647) at text/qtextlayout.cpp:1705
#21 0x0136f4be in QTextLine::setLineWidth (this=0xbfcf6f20, width=8388607) at text/qtextlayout.cpp:1550
#22 0x013ad126 in QTextDocumentLayoutPrivate::layoutBlock (this=0xb50b8f8, bl=..., blockPosition=105, blockFormat=..., layoutStruct=0xbfcf753c, layoutFrom=0, layoutTo=2147483647, 
    previousBlockFormat=0x0) at text/qtextdocumentlayout.cpp:2601
#23 0x013aff3f in QTextDocumentLayoutPrivate::layoutFlow (this=0xb50b8f8, it=..., layoutStruct=0xbfcf753c, layoutFrom=0, layoutTo=2147483647, width=...) at text/qtextdocumentlayout.cpp:2404
#24 0x013b172b in QTextDocumentLayoutPrivate::layoutCell (this=0xb50b8f8, t=0xbb32bf8, cell=..., width=..., layoutFrom=0, layoutTo=2147483647, td=0xbb2f5a8, absoluteTableY=..., withPageBreaks=false)
    at text/qtextdocumentlayout.cpp:1534
#25 0x013b2342 in QTextDocumentLayoutPrivate::layoutTable (this=0xb50b8f8, table=0xbb32bf8, layoutFrom=0, layoutTo=2147483647, parentY=<value optimized out>) at text/qtextdocumentlayout.cpp:1644
#26 0x013b516e in QTextDocumentLayoutPrivate::layoutFrame (this=0xb50b8f8, f=0xbb32bf8, layoutFrom=0, layoutTo=2147483647, frameWidth=<value optimized out>, frameHeight=..., parentY=...)
    at text/qtextdocumentlayout.cpp:2109
#27 0x013af96a in QTextDocumentLayoutPrivate::layoutFlow (this=0xb50b8f8, it=..., layoutStruct=0xbfcf821c, layoutFrom=0, layoutTo=2147483647, width=...) at text/qtextdocumentlayout.cpp:2311
#28 0x013b172b in QTextDocumentLayoutPrivate::layoutCell (this=0xb50b8f8, t=0xb50d440, cell=..., width=..., layoutFrom=0, layoutTo=2147483647, td=0xbb33410, absoluteTableY=..., withPageBreaks=false)
    at text/qtextdocumentlayout.cpp:1534
#29 0x013b2342 in QTextDocumentLayoutPrivate::layoutTable (this=0xb50b8f8, table=0xb50d440, layoutFrom=0, layoutTo=2147483647, parentY=<value optimized out>) at text/qtextdocumentlayout.cpp:1644
#30 0x013b516e in QTextDocumentLayoutPrivate::layoutFrame (this=0xb50b8f8, f=0xb50d440, layoutFrom=0, layoutTo=2147483647, frameWidth=<value optimized out>, frameHeight=..., parentY=...)
    at text/qtextdocumentlayout.cpp:2109
#31 0x013b5a06 in QTextDocumentLayoutPrivate::layoutFrame (this=0xb50b8f8, f=0xb50d440, layoutFrom=0, layoutTo=2147483647, parentY=...) at text/qtextdocumentlayout.cpp:2051
#32 0x013b05c8 in QTextDocumentLayoutPrivate::layoutFlow (this=0xb50b8f8, it=..., layoutStruct=0xbfcf8d60, layoutFrom=0, layoutTo=2147483647, width=...) at text/qtextdocumentlayout.cpp:2313
#33 0x013b53d9 in QTextDocumentLayoutPrivate::layoutFrame (this=0xb50b8f8, f=0xaaa6fb0, layoutFrom=0, layoutTo=2147483647, frameWidth=<value optimized out>, frameHeight=..., parentY=...)
    at text/qtextdocumentlayout.cpp:2145
#34 0x013b5a06 in QTextDocumentLayoutPrivate::layoutFrame (this=0xb50b8f8, f=0xaaa6fb0, layoutFrom=0, layoutTo=2147483647, parentY=...) at text/qtextdocumentlayout.cpp:2051
#35 0x013b5c44 in QTextDocumentLayout::doLayout (this=0xb2c9bf8, from=0, oldLength=0, length=2147483647) at text/qtextdocumentlayout.cpp:2915
#36 0x013b5ce1 in QTextDocumentLayoutPrivate::ensureLayoutedByPosition (this=0xb50b8f8, position=1000) at text/qtextdocumentlayout.cpp:3077
#37 0x013b5f42 in QTextDocumentLayoutPrivate::layoutStep (this=0xb50b8f8) at text/qtextdocumentlayout.cpp:3083
#38 0x013b64d9 in QTextDocumentLayout::documentChanged (this=0xb2c9bf8, from=0, oldLength=0, length=109) at text/qtextdocumentlayout.cpp:2875
#39 0x01394353 in QTextDocumentPrivate::finishEdit (this=0xb2accc8) at text/qtextdocument_p.cpp:1142
#40 0x0138cf91 in QTextDocument::setHtml (this=0x9d20c80, html=...) at text/qtextdocument.cpp:1131
#41 0x0153c422 in QLabelPrivate::ensureTextPopulated (this=0xb2c9c98) at widgets/qlabel.cpp:1452
#42 0x0153c5e0 in QLabelPrivate::ensureTextLayouted (this=0xb2c9c98) at widgets/qlabel.cpp:1468
#43 0x0153d8d8 in QLabelPrivate::sizeForWidth (this=0xb2c9c98, w=-1) at widgets/qlabel.cpp:651
#44 0x0153e0a6 in QLabel::minimumSizeHint (this=0xb566970) at widgets/qlabel.cpp:807
#45 0x0153e1cb in QLabel::sizeHint (this=0x0) at widgets/qlabel.cpp:790
#46 0x01136d99 in QTipLabel::reuseTip (this=0xb566970, text=...) at kernel/qtooltip.cpp:217
#47 0x011372fa in QTipLabel (this=0xb566970, text=..., w=0xae46930) at kernel/qtooltip.cpp:190
#48 0x01137a18 in QToolTip::showText (pos=..., text=..., w=0xae46930, rect=...) at kernel/qtooltip.cpp:456
#49 0xb413fd26 in KMail::FolderView::event (this=0xae46858, e=0xbfcf98dc) at ../../kmail/folderview.cpp:1227
#50 0x010f1c6c in QApplicationPrivate::notify_helper (this=0x9a9f030, receiver=0xae46858, e=0xbfcf98dc) at kernel/qapplication.cpp:4277
#51 0x010f9310 in QApplication::notify (this=0xbfcfa194, receiver=0xae46930, e=0xbfcf9a64) at kernel/qapplication.cpp:4002
#52 0x0067a14a in KApplication::notify (this=0xbfcfa194, receiver=0xae46930, event=0xbfcf9a64) at ../../kdeui/kernel/kapplication.cpp:302
#53 0x00bfe9cb in QCoreApplication::notifyInternal (this=0xbfcfa194, receiver=0xae46930, event=0xbfcf9a64) at kernel/qcoreapplication.cpp:704
#54 0x0110001e in QCoreApplication::sendEvent (receiver=0xae46930, event=0x1a0a020) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#55 0x010f6ca1 in QApplication::event (this=0xbfcfa194, e=0xbfcf9e30) at kernel/qapplication.cpp:2376
#56 0x010f1c6c in QApplicationPrivate::notify_helper (this=0x9a9f030, receiver=0xbfcfa194, e=0xbfcf9e30) at kernel/qapplication.cpp:4277
#57 0x010f8a1e in QApplication::notify (this=0xbfcfa194, receiver=0xbfcfa194, e=0xbfcf9e30) at kernel/qapplication.cpp:3702
#58 0x0067a14a in KApplication::notify (this=0xbfcfa194, receiver=0xbfcfa194, event=0xbfcf9e30) at ../../kdeui/kernel/kapplication.cpp:302
#59 0x00bfe9cb in QCoreApplication::notifyInternal (this=0xbfcfa194, receiver=0xbfcfa194, event=0xbfcf9e30) at kernel/qcoreapplication.cpp:704
#60 0x00c2db86 in QCoreApplication::sendEvent (this=0x9aa8f7c) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#61 QTimerInfoList::activateTimers (this=0x9aa8f7c) at kernel/qeventdispatcher_unix.cpp:603
#62 0x00c2a837 in timerSourceDispatch (source=0x9aa8fb0) at kernel/qeventdispatcher_glib.cpp:184
#63 idleTimerSourceDispatch (source=0x9aa8fb0) at kernel/qeventdispatcher_glib.cpp:231
#64 0x0749ae78 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#65 0x0749e720 in ?? () from /lib/libglib-2.0.so.0
#66 0x0749e853 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#67 0x00c2a4f5 in QEventDispatcherGlib::processEvents (this=0x9a8fad0, flags=...) at kernel/qeventdispatcher_glib.cpp:407
#68 0x011a5635 in QGuiEventDispatcherGlib::processEvents (this=0x9a8fad0, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#69 0x00bfd019 in QEventLoop::processEvents (this=0xbfcfa0f4, flags=) at kernel/qeventloop.cpp:149
#70 0x00bfd46a in QEventLoop::exec (this=0xbfcfa0f4, flags=...) at kernel/qeventloop.cpp:201
#71 0x00c0162f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#72 0x010f1d07 in QApplication::exec () at kernel/qapplication.cpp:3616
#73 0x0804b4e6 in main (argc=1, argv=0xbfcfa3b4) at ../../../kontact/src/main.cpp:218

Reported using DrKonqi