Version:           2.2.2 (using KDE 4.2.2)
OS:                Linux
Installed from:    Debian testing/unstable Packages

The application crashes if I try to close the model in any possible way (File->Load, File->New, File->Close).

Here is the backtrace:

This backtrace appears to be of no use.
This is probably because your packages are built in a way which prevents creation of proper backtraces, or the stack frame was seriously corrupted in the crash.

(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0x7fb140f4e750 (LWP 4904)]
0x00007fb13d0158a0 in __nanosleep_nocancel () from /lib/libc.so.6
[Current thread is 0 (process 4904)]

Thread 1 (Thread 0x7fb140f4e750 (LWP 4904)):
#0  0x00007fb13d0158a0 in __nanosleep_nocancel () from /lib/libc.so.6
#1  0x00007fb13d0156f7 in __sleep (seconds=<value optimized out>) at ../sysdeps/unix/sysv/linux/sleep.c:138
#2  0x00007fb13fabbd09 in KCrash::startDrKonqi (argv=0x7fff4906b428, argc=17) at ../../kdeui/util/kcrash.cpp:412
#3  0x00007fb13fabc65a in KCrash::defaultCrashHandler (sig=11) at ../../kdeui/util/kcrash.cpp:337
#4  <signal handler called>
#5  0x0000000000000000 in ?? ()
#6  0x00007fb13d82963e in __dynamic_cast () from /usr/lib/libstdc++.so.6
#7  0x0000000000bebc8c in ?? ()
#8  0x0000000000becc35 in ?? ()
#9  0x0000000000bed3c5 in ?? ()
#10 0x0000000000c28775 in ?? ()
#11 0x0000000000c2c573 in ?? ()
#12 0x0000000000c17883 in ?? ()
#13 0x0000000000c179b7 in ?? ()
#14 0x0000000000c180dd in ?? ()
#15 0x00007fb13e1066e4 in QMetaObject::activate (sender=0x1f134a0, from_signal_index=<value optimized out>, to_signal_index=6, argv=0xcf67a0) at kernel/qobject.cpp:3031
#16 0x00007fb13e59ed77 in QAction::triggered (this=0x7fb13d2c5a60, _t1=false) at .moc/release-shared/moc_qaction.cpp:216
#17 0x00007fb13e59f540 in QAction::activate (this=0x1f134a0, event=<value optimized out>) at kernel/qaction.cpp:1125
#18 0x00007fb13e936abd in QMenuPrivate::activateAction (this=0x2236170, action=0x1f134a0, action_e=QAction::Trigger, self=true) at widgets/qmenu.cpp:1002
#19 0x00007fb13fb26da1 in KMenu::mouseReleaseEvent (this=0x2236130, e=0x7fff4906ca90) at ../../kdeui/widgets/kmenu.cpp:454
#20 0x00007fb13e5f7139 in QWidget::event (this=0x2236130, event=0x7fff4906ca90) at kernel/qwidget.cpp:7163
#21 0x00007fb13e93929b in QMenu::event (this=0x2236130, e=0x7fff4906ca90) at widgets/qmenu.cpp:2265
#22 0x00007fb13e5a4a5d in QApplicationPrivate::notify_helper (this=0x1e8c860, receiver=0x2236130, e=0x7fff4906ca90) at kernel/qapplication.cpp:3803
#23 0x00007fb13e5ad04a in QApplication::notify (this=<value optimized out>, receiver=0x2236130, e=0x7fff4906ca90) at kernel/qapplication.cpp:3528
#24 0x00007fb13fa5655b in KApplication::notify (this=0x7fff4906d710, receiver=0x2236130, event=0x7fff4906ca90) at ../../kdeui/kernel/kapplication.cpp:307
#25 0x00007fb13e0f2391 in QCoreApplication::notifyInternal (this=0x7fff4906d710, receiver=0x2236130, event=0x7fff4906ca90) at kernel/qcoreapplication.cpp:587
#26 0x00007fb13e5ac3e8 in QApplicationPrivate::sendMouseEvent (receiver=0x2236130, event=0x7fff4906ca90, alienWidget=0x0, nativeWidget=0x2236130, buttonDown=<value optimized out>, 
    lastMouseReceiver=@0x7fb13ef2a0e0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:212
#27 0x00007fb13e610af4 in QETWidget::translateMouseEvent (this=0x2236130, event=<value optimized out>) at kernel/qapplication_x11.cpp:3978
#28 0x00007fb13e60f82f in QApplication::x11ProcessEvent (this=0x8b, event=0x7fff4906d350) at kernel/qapplication_x11.cpp:3162
#29 0x00007fb13e636cb4 in x11EventSourceDispatch (s=0x1e90600, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142
#30 0x00007fb139e1ee4a in IA__g_main_context_dispatch (context=0x1e8f520) at /tmp/buildd/glib2.0-2.20.0/glib/gmain.c:1814
#31 0x00007fb139e22510 in g_main_context_iterate (context=0x1e8f520, block=1, dispatch=1, self=<value optimized out>) at /tmp/buildd/glib2.0-2.20.0/glib/gmain.c:2448
#32 0x00007fb139e226ac in IA__g_main_context_iteration (context=0x1e8f520, may_block=1) at /tmp/buildd/glib2.0-2.20.0/glib/gmain.c:2511
#33 0x00007fb13e11a71f in QEventDispatcherGlib::processEvents (this=0x1e8ca40, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319
#34 0x00007fb13e63647f in QGuiEventDispatcherGlib::processEvents (this=0x7fb13d2c5a60, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:198
#35 0x00007fb13e0f0cb2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1225184832}) at kernel/qeventloop.cpp:143
#36 0x00007fb13e0f0e3d in QEventLoop::exec (this=0x7fff4906d680, flags={i = 1225184912}) at kernel/qeventloop.cpp:194
#37 0x00007fb13e0f32ed in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#38 0x0000000000bc8c75 in ?? ()
#39 0x00007fb13cf955a6 in __libc_start_main (main=0xbc8300, argc=1, ubp_av=0x7fff4906db38, init=0xc8f080 <__libc_csu_init>, fini=<value optimized out>, rtld_fini=<value optimized out>, 
    stack_end=0x7fff4906db28) at libc-start.c:222
#40 0x0000000000433939 in _start ()
#0  0x00007fb13d0158a0 in __nanosleep_nocancel () from /lib/libc.so.6