Application that crashed: konqueror
Version of the application: 4.3.2 (KDE 4.3.2)
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-14-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I was testing avahi between a server and my laptop. The following was observed on my laptop:

1) Had Dolphin open.
2) Navigated to "Places->Network" in order to browse through the services announced by my server through avahi.
3) Selected my server.
4) The server announced "Digital Audio Access", a web page, and a folder.
5) I selected the web page by double-clicking.
6) Two konqueror instances came up - one of them crashed, the other opened the page successfully.

 -- Backtrace:
Application: Konqueror (konqueror), signal: Segmentation fault
[KCrash Handler]
#6  DOM::DocumentImpl::view (this=0xb2370040) at ../../khtml/xml/dom_docimpl.cpp:2907
#7  0x0250e959 in KJS::XMLHttpRequest::slotData (this=0xb2370040, _data=...) at ../../khtml/ecma/xmlhttprequest.cpp:750
#8  0x0250f4b3 in KJS::XMLHttpRequestQObject::slotData (this=0x9217fc8, _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0xbfa47744) at ../../khtml/ecma/xmlhttprequest.cpp:87
#9  KJS::XMLHttpRequestQObject::qt_metacall (this=0x9217fc8, _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0xbfa47744) at ./xmlhttprequest.moc:71
#10 0x01fba263 in QMetaObject::activate (sender=0x91bf990, from_signal_index=40, to_signal_index=40, argv=0xbfa47744) at kernel/qobject.cpp:3113
#11 0x01fbaec2 in QMetaObject::activate (sender=0x91bf990, m=0xe3a350, local_signal_index=0, argv=0xbfa47744) at kernel/qobject.cpp:3187
#12 0x00c827a9 in KIO::TransferJob::data (this=0x91bf990, _t1=0x91bf990, _t2=...) at ./jobclasses.moc:364
#13 0x00c82ff2 in KIO::TransferJob::slotData (this=0x91bf990, _data=...) at ../../kio/kio/job.cpp:903
#14 0x00c888c5 in KIO::TransferJob::qt_metacall (this=0x91bf990, _c=QMetaObject::InvokeMetaMethod, _id=48, _a=0xbfa47898) at ./jobclasses.moc:344
#15 0x01fba263 in QMetaObject::activate (sender=0x90ead50, from_signal_index=4, to_signal_index=4, argv=0xbfa47898) at kernel/qobject.cpp:3113
#16 0x01fbaec2 in QMetaObject::activate (sender=0x90ead50, m=0xe3cf64, local_signal_index=0, argv=0xbfa47898) at kernel/qobject.cpp:3187
#17 0x00d54673 in KIO::SlaveInterface::data (this=0x90ead50, _t1=...) at ./slaveinterface.moc:140
#18 0x00d585d7 in KIO::SlaveInterface::dispatch (this=0x90ead50, _cmd=100, rawdata=...) at ../../kio/kio/slaveinterface.cpp:163
#19 0x00d54a13 in KIO::SlaveInterface::dispatch (this=0x90ead50) at ../../kio/kio/slaveinterface.cpp:91
#20 0x00d46aea in KIO::Slave::gotInput (this=0x90ead50) at ../../kio/kio/slave.cpp:322
#21 0x00d48ee3 in KIO::Slave::qt_metacall (this=0x90ead50, _c=QMetaObject::InvokeMetaMethod, _id=30, _a=0xbfa47b2c) at ./slave.moc:76
#22 0x01fba263 in QMetaObject::activate (sender=0x90f6258, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#23 0x01fbaec2 in QMetaObject::activate (sender=0x90f6258, m=0xe398a0, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3187
#24 0x00c50f97 in KIO::Connection::readyRead (this=0x90f6258) at ./connection.moc:86
#25 0x00c52d5e in KIO::ConnectionPrivate::dequeue (this=0x90f6268) at ../../kio/kio/connection.cpp:82
#26 0x00c52e8e in KIO::Connection::qt_metacall (this=0x90f6258, _c=QMetaObject::InvokeMetaMethod, _id=5, _a=0x910d480) at ./connection.moc:73
#27 0x01fb2f0b in QMetaCallEvent::placeMetaCall (this=0x8b5ca60, object=0x90f6258) at kernel/qobject.cpp:477
#28 0x01fb45fe in QObject::event (this=0x90f6258, e=0x8b5ca60) at kernel/qobject.cpp:1111
#29 0x012f7f54 in QApplicationPrivate::notify_helper (this=0x8b73ca8, receiver=0x90f6258, e=0x8b5ca60) at kernel/qapplication.cpp:4056
#30 0x012ff67c in QApplication::notify (this=0xbfa48464, receiver=0x90f6258, e=0x8b5ca60) at kernel/qapplication.cpp:3603
#31 0x01017bfa in KApplication::notify (this=0xbfa48464, receiver=0x90f6258, event=0x8b5ca60) at ../../kdeui/kernel/kapplication.cpp:302
#32 0x01fa46cb in QCoreApplication::notifyInternal (this=0xbfa48464, receiver=0x90f6258, event=0x8b5ca60) at kernel/qcoreapplication.cpp:610
#33 0x01fa52b2 in QCoreApplication::sendEvent (receiver=0x0, event_type=0, data=0x8b5b800) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#34 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x8b5b800) at kernel/qcoreapplication.cpp:1247
#35 0x01fa547d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#36 0x01fcf3ff in QCoreApplication::sendPostedEvents (s=0x8b76110) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#37 postEventSourceDispatch (s=0x8b76110) at kernel/qeventdispatcher_glib.cpp:210
#38 0x05ae9e78 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#39 0x05aed720 in ?? () from /lib/libglib-2.0.so.0
#40 0x05aed853 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#41 0x01fcf02c in QEventDispatcherGlib::processEvents (this=0x8b5b9d8, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#42 0x01398be5 in QGuiEventDispatcherGlib::processEvents (this=0x8b5b9d8, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#43 0x01fa2c79 in QEventLoop::processEvents (this=0xbfa48324, flags=) at kernel/qeventloop.cpp:149
#44 0x01fa30ca in QEventLoop::exec (this=0xbfa48324, flags=...) at kernel/qeventloop.cpp:201
#45 0x01fa553f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#46 0x012f7dd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#47 0x0045059f in kdemain () from /usr/lib/libkdeinit4_konqueror.so
#48 0x080485cb in _start ()

Reported using DrKonqi