Version:           unknown (using KDE 3.3.90 (alpha1, CVS >= 20041206), Gentoo)
Compiler:          gcc version 3.3.4 20040623 (Gentoo Linux 3.3.4-r1, ssp-3.3.2-2, pie-8.7.6)
OS:                Linux (i686) release 2.6.9

I was watching a video and I press back, konqueror crash

I'm not sure if this is the same as bug #90874
I'm also using embedded kaffeine

but I thought that be usefull for you to get my version and everything.

here is the stacktrace

Using host libthread_db library "/lib/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 16384 (LWP 29607)]
[New Thread 32769 (LWP 29610)]
[Thread debugging using libthread_db enabled]
[New Thread 16384 (LWP 29607)]
[New Thread 32769 (LWP 29610)]
[Thread debugging using libthread_db enabled]
[New Thread 16384 (LWP 29607)]
[New Thread 32769 (LWP 29610)]
[New Thread 245762 (LWP 24722)]
[New Thread 262147 (LWP 24723)]
[New Thread 278532 (LWP 24724)]
[New Thread 294917 (LWP 24725)]
[New Thread 311302 (LWP 24726)]
[New Thread 327687 (LWP 24727)]
[New Thread 344072 (LWP 24728)]
[New Thread 360457 (LWP 25075)]
[KCrash handler]
#6  0xb6a33aa1 in pthread_mutex_lock () from /lib/libpthread.so.0
#7  0xb6aedbfc in _XLockMutex () from /usr/X11R6/lib/libX11.so.6
#8  0xb6ad7b38 in XrmQGetResource () from /usr/X11R6/lib/libX11.so.6
#9  0xb6ad7ba8 in XrmGetResource () from /usr/X11R6/lib/libX11.so.6
#10 0xb6ab629c in XGetErrorDatabaseText () from /usr/X11R6/lib/libX11.so.6
#11 0xb6ab61bb in XGetErrorText () from /usr/X11R6/lib/libX11.so.6
#12 0xb6f01644 in qt_x_errhandler (dpy=0x8105b80, err=0xbfffde20)
    at kernel/qapplication_x11.cpp:706
#13 0xb77df5f7 in KApplication::xErrhandler(_XDisplay*, void*) (
    this=0xb6aedbdb, dpy=0xb6aedbdb, err_=0xb6aedbdb) at kapplication.cpp:727
#14 0xb77eaf49 in kde_x_errhandler (dpy=0x27, err=0x27) at kapplication.cpp:177
#15 0xb6ad2ad8 in _XError () from /usr/X11R6/lib/libX11.so.6
#16 0xb6ad18d4 in _XReply () from /usr/X11R6/lib/libX11.so.6
#17 0xb6acd79e in XSync () from /usr/X11R6/lib/libX11.so.6
#18 0xb7a9d87c in ~QXEmbed (this=0x92533f0) at qxembed.cpp:695
#19 0xb5d9b6ae in ~NSPluginInstance (this=0x92533f0) at nspluginloader.cpp:73
#20 0xb5d97dab in PluginPart::closeURL() (this=0x92b64c0)
    at plugin_part.cpp:303
#21 0xb61ecf60 in KHTMLPart::closeURL() (this=0x925d288) at khtml_part.cpp:811
#22 0xb61ece89 in KHTMLPart::closeURL() (this=0x8890900) at khtml_part.cpp:801
#23 0xb62023ab in KHTMLPart::restoreState(QDataStream&) (this=0x8890900, 
    stream=@0xbfffe4e0) at khtml_part.cpp:5186
#24 0xb621c595 in KHTMLPartBrowserExtension::restoreState(QDataStream&) (
    this=0x27, stream=@0xb6aedbdb) at khtml_ext.cpp:99
#25 0xb66ea687 in KonqView::go(int) (this=0x83a9bb0, steps=-1237053784)
    at konq_view.cc:814
#26 0xb6724742 in KonqMainWindow::slotGoHistoryDelayed() (this=0x8183e30)
    at konq_mainwindow.cc:3001
#27 0xb67361ca in KonqMainWindow::qt_invoke(int, QUObject*) (this=0x8183e30, 
    _id=177, _o=0xbfffe7b0) at konq_mainwindow.moc:658
#28 0xb6fff794 in QObject::activate_signal(QConnectionList*, QUObject*) (
    this=0x82a4dd0, clist=0x92a47b8, o=0xbfffe7b0) at kernel/qobject.cpp:2357
#29 0xb73df0ef in QSignal::signal(QVariant const&) (this=0x82a4dd0, 
    t0=@0x82a4df8) at .moc/debug-shared-mt/moc_qsignal.cpp:100
#30 0xb702161f in QSignal::activate() (this=0x82a4dd0)
    at kernel/qsignal.cpp:212
#31 0xb702b2ea in QSingleShotTimer::event(QEvent*) (this=0x82a4da8)
    at kernel/qtimer.cpp:277
#32 0xb6f8f5a9 in QApplication::internalNotify(QObject*, QEvent*) (
    this=0xbffff060, receiver=0x82a4da8, e=0xbfffeb10)
    at kernel/qapplication.cpp:2635
#33 0xb6f8e7ec in QApplication::notify(QObject*, QEvent*) (this=0xbffff060, 
    receiver=0x82a4da8, e=0xbfffeb10) at kernel/qapplication.cpp:2358
#34 0xb77dd9f5 in KApplication::notify(QObject*, QEvent*) (this=0xbffff060, 
    receiver=0x82a4da8, event=0xbfffeb10) at kapplication.cpp:543
#35 0xb7fceebf in QApplication::sendEvent(QObject*, QEvent*) (
    receiver=0xb6aedbdb, event=0x86ca9dc) at qapplication.h:491
#36 0xb6f7ab59 in QEventLoop::activateTimers() (this=0x812e288)
    at kernel/qeventloop_unix.cpp:558
#37 0xb6f2b48d in QEventLoop::processEvents(unsigned) (this=0x812e288, flags=4)
    at kernel/qeventloop_x11.cpp:389
#38 0xb6fa6979 in QEventLoop::enterLoop() (this=0x812e288)
    at kernel/qeventloop.cpp:198
#39 0xb6fa6892 in QEventLoop::exec() (this=0x812e288)
    at kernel/qeventloop.cpp:145
#40 0xb6f8f74b in QApplication::exec() (this=0xbffff060)
    at kernel/qapplication.cpp:2758
#41 0xb66d899a in kdemain (argc=-1230054437, argv=0xb6aedbdb)
    at konq_main.cc:206
#42 0xb76c27e2 in kdeinitmain (argc=-1230054437, argv=0xb6aedbdb)
    at konqueror_dummy.cc:2
#43 0x0804e342 in launch (argc=2, _name=0x810295c "konqueror", 
    args=0x810296f "\001", cwd=0x0, envc=1, envs=0x8102980 "", 
    reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0xb6aedbdb "U\211å\203ì\b\213M\b\211]üèÛ\027üÿ\201ø\200\a")
    at kinit.cpp:623
#44 0x08050742 in handle_launcher_request (sock=8) at kinit.cpp:1187
#45 0x0804f54a in handle_requests (waitForPid=0) at kinit.cpp:1388
#46 0x0804d71b in main (argc=2, argv=0xbffff764, envp=0xb6aedbdb)
    at kinit.cpp:1841