Thanks for the bug report! Can you provide a backtrace of the crash? See
http://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports

Without a way to reproduce the bug or at least a backtrace, there's not much that can be done :-(

I provide a segment fault backtrace. I was using Konqueror with 4 tabs open. When closing one of them Konqueror crashed. It occurs randomly, but I suspect it occurs more often when RAM memory is mostly in used (my laptop has just 1GB RAM which is filled quickly so the system goes slow by using SWAP):

--------------------------
Application: Konqueror (kdeinit4), signal: Segmentation fault
[KCrash Handler]
#5  KonqMainWindow::slotAddClosedUrl (this=0x84cbe0, tab=0x27b6b78) at /build/buildd/kdebase-4.3.2/apps/konqueror/src/konqmainwindow.cpp:5189
#6  0x00007fbda2f76c74 in KonqMainWindow::qt_metacall (this=0x84cbe0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff436a4fe0)
    at /build/buildd/kdebase-4.3.2/obj-x86_64-linux-gnu/apps/konqueror/src/konqmainwindow.moc:379
#7  0x00007fbdaf071ea2 in QMetaObject::activate (sender=0x8519d0, from_signal_index=<value optimized out>, to_signal_index=10, argv=0x7fbda31c8da0) at kernel/qobject.cpp:3113
#8  0x00007fbda2f21c1f in KonqViewManager::aboutToRemoveTab (this=0x7fbda31c7e80, _t1=0x27b6b78) at /build/buildd/kdebase-4.3.2/obj-x86_64-linux-gnu/apps/konqueror/src/konqviewmanager.moc:106
#9  0x00007fbda2f227fb in KonqViewManager::removeTab (this=0x8519d0, currentFrame=0x27b6b78, emitAboutToRemoveSignal=true) at /build/buildd/kdebase-4.3.2/apps/konqueror/src/konqviewmanager.cpp:389
#10 0x00007fbda2f77185 in KonqMainWindow::qt_metacall (this=0x84cbe0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff436a5260)
    at /build/buildd/kdebase-4.3.2/obj-x86_64-linux-gnu/apps/konqueror/src/konqmainwindow.moc:417
#11 0x00007fbdaf071ea2 in QMetaObject::activate (sender=0x9c19a70, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x7fbda31c8da0) at kernel/qobject.cpp:3113
#12 0x00007fbdaf07714f in QSingleShotTimer::timerEvent (this=0x9c19a70) at kernel/qtimer.cpp:298
#13 0x00007fbdaf06c263 in QObject::event (this=0x9c19a70, e=0x7fff436a4bb0) at kernel/qobject.cpp:1075
#14 0x00007fbdac621f4d in QApplicationPrivate::notify_helper (this=0x76fd50, receiver=0x9c19a70, e=0x7fff436a5920) at kernel/qapplication.cpp:4056
#15 0x00007fbdac62a18a in QApplication::notify (this=0x7fff436a5e50, receiver=0x9c19a70, e=0x7fff436a5920) at kernel/qapplication.cpp:4021
#16 0x00007fbdad734abb in KApplication::notify (this=0x7fff436a5e50, receiver=0x9c19a70, event=0x7fff436a5920) at /build/buildd/kde4libs-4.3.2/kdeui/kernel/kapplication.cpp:302
#17 0x00007fbdaf05c6ac in QCoreApplication::notifyInternal (this=0x7fff436a5e50, receiver=0x9c19a70, event=0x7fff436a5920) at kernel/qcoreapplication.cpp:610
#18 0x00007fbdaf089516 in QTimerInfoList::activateTimers (this=0x773a20) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#19 0x00007fbdaf085b2d in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:165
#20 0x00007fbdab0b320a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#21 0x00007fbdab0b68e0 in ?? () from /usr/lib/libglib-2.0.so.0
#22 0x00007fbdab0b6a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#23 0x00007fbdaf085a8f in QEventDispatcherGlib::processEvents (this=0x6e1e70, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#24 0x00007fbdac6babdf in QGuiEventDispatcherGlib::processEvents (this=0x7fbda31c7e80, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#25 0x00007fbdaf05af42 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1131043728}) at kernel/qeventloop.cpp:149
#26 0x00007fbdaf05b314 in QEventLoop::exec (this=0x7fff436a5bd0, flags={i = 1131043808}) at kernel/qeventloop.cpp:201
#27 0x00007fbdaf05d5e4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#28 0x00007fbda2fa24e2 in kdemain (argc=<value optimized out>, argv=<value optimized out>) at /build/buildd/kdebase-4.3.2/apps/konqueror/src/konqmain.cpp:271
#29 0x0000000000407215 in launch (argc=3, _name=0x722ae8 "konqueror", args=<value optimized out>, cwd=0x0, envc=0, envs=0x722b3d "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x40a3a1 "0") at /build/buildd/kde4libs-4.3.2/kinit/kinit.cpp:677
#30 0x0000000000407a38 in handle_launcher_request (sock=7, who=<value optimized out>) at /build/buildd/kde4libs-4.3.2/kinit/kinit.cpp:1169
#31 0x0000000000407fe5 in handle_requests (waitForPid=0) at /build/buildd/kde4libs-4.3.2/kinit/kinit.cpp:1362
#32 0x0000000000408b26 in main (argc=2, argv=0x7fff436a7538, envp=0x7fff436a7550) at /build/buildd/kde4libs-4.3.2/kinit/kinit.cpp:1793
--------------------------

Thanks for the backtrace! This issue is known already (and I hope somebody will have some time to fix it soon - I think it's more or less clear what the problem is).

*** This bug has been marked as a duplicate of bug 150162 ***