Version:           3.4.2 (using KDE 3.4.2, Debian Package 4:3.4.2-4 (testing/unstable))
Compiler:          Target: i486-linux-gnu
OS:                Linux (i686) release 2.4.21-rc1

The crash happened when one of the tabs showed the site http://www.ejbdotcom.net/content/1145.html (very funny btw ;-)) and I switched to a different tab hiding the other one. Here's the bt:

0x4020503b in waitpid () from /lib/libc.so.6
#0  0x4020503b in waitpid () from /lib/libc.so.6
#1  0x407b6e70 in ?? () from /usr/lib/libkdecore.so.4
#2  0x00000001 in ?? ()
#3  0x406f8d0c in KCrash::defaultCrashHandler () from /usr/lib/libkdecore.so.4
#4  0x415dd041 in __pthread_sighandler () from /lib/libpthread.so.0
#5  0x401a5668 in killpg () from /lib/libc.so.6
#6  0x40242970 in pthread_mutex_lock () from /lib/libc.so.6
#7  0x40ff94de in _XUnregisterFilter () from /usr/X11R6/lib/libX11.so.6
#8  0x40fe5c1d in XrmQGetResource () from /usr/X11R6/lib/libX11.so.6
#9  0x40fd9121 in XStringToKeysym () from /usr/X11R6/lib/libX11.so.6
#10 0x4069e104 in KKeyServer::Sym::init () from /usr/lib/libkdecore.so.4
#11 0x406bb23b in KKey::init () from /usr/lib/libkdecore.so.4
#12 0x406bb2f0 in KKey::KKey () from /usr/lib/libkdecore.so.4
#13 0x406bb463 in KKeySequence::init () from /usr/lib/libkdecore.so.4
#14 0x406bb61a in KShortcut::init () from /usr/lib/libkdecore.so.4
#15 0x406bba02 in KShortcut::KShortcut () from /usr/lib/libkdecore.so.4
#16 0x411be42d in KAction::setShortcutText () from /usr/lib/libkdeui.so.4
#17 0x4123dd3f in KAction::qt_property () from /usr/lib/libkdeui.so.4
#18 0x41c42236 in KHTMLZoomFactorAction::qt_property ()
   from /usr/lib/libkhtml.so.4
#19 0x40acbbae in QObject::setProperty () from /usr/lib/libqt-mt.so.3
#20 0x4127f8f2 in KXMLGUIFactory::configureAction ()
   from /usr/lib/libkdeui.so.4
#21 0x4127fab4 in KXMLGUIFactory::configureAction ()
   from /usr/lib/libkdeui.so.4
#22 0x4127fba4 in KXMLGUIFactory::applyActionProperties ()
   from /usr/lib/libkdeui.so.4
#23 0x412fe723 in KXMLGUIFactory::addClient () from /usr/lib/libkdeui.so.4
#24 0x40060661 in KParts::MainWindow::createGUI ()
   from /usr/lib/libkparts.so.2
#25 0x416f8922 in KonqMainWindow::slotPartActivated ()
   from /usr/lib/libkdeinit_konqueror.so
#26 0x416f9579 in KonqViewManager::emitActivePartChanged ()
   from /usr/lib/libkdeinit_konqueror.so
#27 0x41721d68 in KonqViewManager::qt_invoke ()
   from /usr/lib/libkdeinit_konqueror.so
#28 0x40acac5f in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#29 0x40e5b5a5 in QSignal::signal () from /usr/lib/libqt-mt.so.3
#30 0x40ae8b30 in QSignal::activate () from /usr/lib/libqt-mt.so.3
#31 0x40af0444 in QSingleShotTimer::event () from /usr/lib/libqt-mt.so.3
#32 0x40a60778 in QApplication::internalNotify () from /usr/lib/libqt-mt.so.3
#33 0x40a60996 in QApplication::notify () from /usr/lib/libqt-mt.so.3
#34 0x4071d9fc in KApplication::notify () from /usr/lib/libkdecore.so.4
#35 0x409f0665 in QApplication::sendEvent () from /usr/lib/libqt-mt.so.3
#36 0x40a51a44 in QEventLoop::activateTimers () from /usr/lib/libqt-mt.so.3
#37 0x40a043f8 in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#38 0x40a78ea2 in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#39 0x40a78dcb in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#40 0x40a5f305 in QApplication::exec () from /usr/lib/libqt-mt.so.3
#41 0x417202ac in kdemain () from /usr/lib/libkdeinit_konqueror.so
#42 0x4001a530 in kdeinitmain () from /usr/lib/kde3/konqueror.so