Version:            (using KDE KDE 3.5.5)
Installed from:    Ubuntu Packages
OS:                Linux

I can't reproduce this anymore, so not sure how useful this report is, but here it is anyway. As I was trying to open http://youtube.com/watch?v=C4SgPMWtzAs, Konqueror crashed with the following backtrace:

[KCrash handler]
#6  0xb758bd57 in QGList::first () from /usr/lib/libqt-mt.so.3
#7  0xb60fe4b4 in TestFunctionImp::call () from /usr/lib/libkhtml.so.4
#8  0xb60fea75 in TestFunctionImp::call () from /usr/lib/libkhtml.so.4
#9  0xb5e408ea in KJS::Reference::getValue () from /usr/lib/libkjs.so.1
#10 0xb5e40e29 in KJS::Reference::getValue () from /usr/lib/libkjs.so.1
#11 0xb5e17733 in KJS::DateObjectFuncImp::implementsCall ()
   from /usr/lib/libkjs.so.1
#12 0xb5e41751 in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#13 0xb5e4162f in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#14 0xb5e59000 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#15 0xb5e5a238 in KJS::Interpreter::evaluate () from /usr/lib/libkjs.so.1
#16 0xb5e58ee9 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#17 0xb5e5879b in KJS::Interpreter::Interpreter () from /usr/lib/libkjs.so.1
#18 0xb5e5a2d8 in KJS::Interpreter::evaluate () from /usr/lib/libkjs.so.1
#19 0xb5e58ee9 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#20 0xb5e58896 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#21 0xb5e41334 in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#22 0xb5e44349 in KJS::Object::call () from /usr/lib/libkjs.so.1
#23 0xb5e4c391 in KJS::UndefinedImp::toObject () from /usr/lib/libkjs.so.1
#24 0xb5e41aac in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#25 0xb5e58cbe in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#26 0xb5e5a2d8 in KJS::Interpreter::evaluate () from /usr/lib/libkjs.so.1
#27 0xb5e58ee9 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#28 0xb5e58896 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#29 0xb5e41334 in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#30 0xb5e26c88 in KJS::DeclaredFunctionImp::construct ()
   from /usr/lib/libkjs.so.1
#31 0xb5e4c7a4 in KJS::UndefinedImp::toObject () from /usr/lib/libkjs.so.1
#32 0xb5e17733 in KJS::DateObjectFuncImp::implementsCall ()
   from /usr/lib/libkjs.so.1
#33 0xb5e41751 in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#34 0xb5e4162f in KJS::FunctionImp::call () from /usr/lib/libkjs.so.1
#35 0xb5e59000 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#36 0xb5e5a238 in KJS::Interpreter::evaluate () from /usr/lib/libkjs.so.1
#37 0xb5e58ee9 in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#38 0xb5e59e6a in KJS::DeclaredFunctionImp::execute ()
   from /usr/lib/libkjs.so.1
#39 0xb5e5a1ca in KJS::Interpreter::evaluate () from /usr/lib/libkjs.so.1
#40 0xb6115a48 in EmbedLiveConnect::get () from /usr/lib/libkhtml.so.4
#41 0xb5f6c72c in KHTMLPart::executeScript () from /usr/lib/libkhtml.so.4
#42 0xb5fed877 in DOM::checkChild () from /usr/lib/libkhtml.so.4
#43 0xb6001be0 in DOM::checkChild () from /usr/lib/libkhtml.so.4
#44 0xb60031fb in DOM::checkChild () from /usr/lib/libkhtml.so.4
#45 0xb600514a in DOM::checkChild () from /usr/lib/libkhtml.so.4
#46 0xb60060f3 in DOM::checkChild () from /usr/lib/libkhtml.so.4
#47 0xb6001417 in DOM::checkChild () from /usr/lib/libkhtml.so.4
#48 0xb60b9ec4 in khtml_jpeg_source_mgr::khtml_jpeg_source_mgr ()
   from /usr/lib/libkhtml.so.4
#49 0xb60c16c1 in KNSPluginWizard::initLicencePage ()
   from /usr/lib/libkhtml.so.4
#50 0xb60c294e in KNSPluginWizard::initLicencePage ()
   from /usr/lib/libkhtml.so.4
#51 0xb60c310a in KNSPluginWizard::initLicencePage ()
   from /usr/lib/libkhtml.so.4
#52 0xb7290957 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#53 0xb7ac977e in KIO::Job::result () from /usr/lib/libkio.so.4
#54 0xb7b09a8d in KIO::Job::emitResult () from /usr/lib/libkio.so.4
#55 0xb7b1d75e in KIO::SimpleJob::slotFinished () from /usr/lib/libkio.so.4
#56 0xb7b1de6d in KIO::TransferJob::slotFinished () from /usr/lib/libkio.so.4
#57 0xb7b096ba in KIO::TransferJob::qt_invoke () from /usr/lib/libkio.so.4
#58 0xb7290957 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#59 0xb72913fc in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#60 0xb7ac3ffc in KIO::SlaveInterface::finished () from /usr/lib/libkio.so.4
#61 0xb7b29720 in KIO::SlaveInterface::dispatch () from /usr/lib/libkio.so.4
#62 0xb7b2775a in KIO::SlaveInterface::dispatch () from /usr/lib/libkio.so.4
#63 0xb7ad843c in KIO::Slave::gotInput () from /usr/lib/libkio.so.4
#64 0xb7b17360 in KIO::Slave::qt_invoke () from /usr/lib/libkio.so.4
#65 0xb7290957 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#66 0xb729126e in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#67 0xb761dcdb in QSocketNotifier::activated () from /usr/lib/libqt-mt.so.3
#68 0xb72b3516 in QSocketNotifier::event () from /usr/lib/libqt-mt.so.3
#69 0xb7227b88 in QApplication::internalNotify () from /usr/lib/libqt-mt.so.3
#70 0xb72299b7 in QApplication::notify () from /usr/lib/libqt-mt.so.3
#71 0xb791ddb2 in KApplication::notify () from /usr/lib/libkdecore.so.4
#72 0xb71ba389 in QApplication::sendEvent () from /usr/lib/libqt-mt.so.3
#73 0xb7219f81 in QEventLoop::activateSocketNotifiers ()
   from /usr/lib/libqt-mt.so.3
#74 0xb71ceea7 in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#75 0xb724225e in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#76 0xb724206e in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#77 0xb7229731 in QApplication::exec () from /usr/lib/libqt-mt.so.3
#78 0xb676f2b4 in kdemain () from /usr/lib/libkdeinit_konqueror.so
#79 0xb7f6f524 in kdeinitmain () from /usr/lib/kde3/konqueror.so
#80 0x0804e4df in ?? ()
#81 0x00000002 in ?? ()
#82 0x080ed430 in ?? ()
#83 0x00000001 in ?? ()
#84 0x00000000 in ?? ()

What I was doing:
Typed "youtu" in the address bar so I could see the history, found a link to a cool video, and copied it so I could send it to a friend. Later, I came back again, typed "b" to get the history again, and actually opened one of the URLs. Konqueror crashed before it displayed any content.