Created attachment 51695 [details]
KRDC crash log

Pasting the backtrace to ease searches:

Application: KRDC (krdc), signal: Segmentation fault
[KCrash Handler]
#5  0x08063aba in MainWindow::saveHostPrefs (this=0x83d3580, view=0x8890fd0) at /var/tmp/portage/kde-base/krdc-4.4.5/work/krdc-4.4.5/krdc/mainwindow.cpp:975
#6  0x0806b5f4 in MainWindow::disconnectHost (this=0x83d3580) at /var/tmp/portage/kde-base/krdc-4.4.5/work/krdc-4.4.5/krdc/mainwindow.cpp:581
#7  0x0806bedf in MainWindow::qt_metacall (this=0x83d3580, _c=QMetaObject::InvokeMetaMethod, _id=143200208, _a=0xbfb62488)
    at /var/tmp/portage/kde-base/krdc-4.4.5/work/krdc-4.4.5_build/krdc/mainwindow.moc:142
#8  0xb6365d2a in QMetaObject::metacall (object=0x83d3580, cl=QMetaObject::InvokeMetaMethod, idx=62, argv=0xbfb62488) at kernel/qmetaobject.cpp:237
#9  0xb6374537 in QMetaObject::activate (sender=0x84105e8, m=0xb711aff8, local_signal_index=1, argv=<value optimized out>) at kernel/qobject.cpp:3285
#10 0xb67ff8ba in QAction::triggered (this=0x84105e8, _t1=false) at .moc/release-shared/moc_qaction.cpp:263
#11 0xb6801acc in QAction::activate (this=0x84105e8, event=QAction::Trigger) at kernel/qaction.cpp:1255
#12 0xb6ce60e3 in QAction::trigger (this=0x1) at ../../include/QtGui/../../src/gui/kernel/qaction.h:218
#13 QToolButton::nextCheckState (this=0x1) at widgets/qtoolbutton.cpp:1147
#14 0xb6c02bf4 in QAbstractButtonPrivate::click (this=0x84ab5b8) at widgets/qabstractbutton.cpp:528
#15 0xb6c02efe in QAbstractButton::mouseReleaseEvent (this=0x84ba558, e=0xbfb62cd4) at widgets/qabstractbutton.cpp:1121
#16 0xb6ce659d in QToolButton::mouseReleaseEvent (this=0x84ba558, e=0xbfb62cd4) at widgets/qtoolbutton.cpp:721
#17 0xb6864430 in QWidget::event (this=0x84ba558, event=0xbfb62cd4) at kernel/qwidget.cpp:7998
#18 0xb6c01c4f in QAbstractButton::event (this=0x84ba558, e=0x1) at widgets/qabstractbutton.cpp:1080
#19 0xb6ce912b in QToolButton::event (this=0x84ba558, event=0xbfb62cd4) at widgets/qtoolbutton.cpp:1163
#20 0xb68061c4 in QApplicationPrivate::notify_helper (this=0x8394c48, receiver=0x84ba558, e=0xbfb62cd4) at kernel/qapplication.cpp:4300
#21 0xb680d933 in QApplication::notify (this=0xbfb634b0, receiver=0x84ba558, e=0xbfb62cd4) at kernel/qapplication.cpp:3865
#22 0xb7311fbb in KApplication::notify (this=0xbfb634b0, receiver=0x84ba558, event=0xbfb62cd4) at /var/tmp/portage/kde-base/kdelibs-4.4.5/work/kdelibs-4.4.5/kdeui/kernel/kapplication.cpp:302
#23 0xb6360ac2 in QCoreApplication::notifyInternal (this=0xbfb634b0, receiver=0x84ba558, event=0xbfb62cd4) at kernel/qcoreapplication.cpp:704
#24 0xb680c678 in QCoreApplication::sendEvent (receiver=0x84ba558, event=0xbfb62cd4, alienWidget=0x84ba558, nativeWidget=0x8495e40, buttonDown=0xb7136038, lastMouseReceiver=..., spontaneous=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#25 QApplicationPrivate::sendMouseEvent (receiver=0x84ba558, event=0xbfb62cd4, alienWidget=0x84ba558, nativeWidget=0x8495e40, buttonDown=0xb7136038, lastMouseReceiver=..., spontaneous=true)
    at kernel/qapplication.cpp:2965
#26 0xb689741c in QETWidget::translateMouseEvent (this=0x8495e40, event=0xbfb63120) at kernel/qapplication_x11.cpp:4368
#27 0xb689697b in QApplication::x11ProcessEvent (this=0xbfb634b0, event=0xbfb63120) at kernel/qapplication_x11.cpp:3379
#28 0xb68c373a in x11EventSourceDispatch (s=0x8397e40, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#29 0xb5979cac in g_main_dispatch (context=0x8397020) at gmain.c:1960
#30 IA__g_main_context_dispatch (context=0x8397020) at gmain.c:2513
#31 0xb597daf0 in g_main_context_iterate (context=0x8397020, block=<value optimized out>, dispatch=1, self=0x83802b8) at gmain.c:2591
#32 0xb597dc99 in IA__g_main_context_iteration (context=0x8397020, may_block=1) at gmain.c:2654
#33 0xb638ca06 in QEventDispatcherGlib::processEvents (this=0x8394c08, flags=...) at kernel/qeventdispatcher_glib.cpp:412
#34 0xb68c3296 in QGuiEventDispatcherGlib::processEvents (this=0x8394c08, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#35 0xb635f09a in QEventLoop::processEvents (this=0xbfb63414, flags=) at kernel/qeventloop.cpp:149
#36 0xb635f4fa in QEventLoop::exec (this=0xbfb63414, flags=...) at kernel/qeventloop.cpp:201
#37 0xb6363711 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#38 0xb6806268 in QApplication::exec () at kernel/qapplication.cpp:3579
#39 0x0806cfba in main (argc=1, argv=0xbfb63694) at /var/tmp/portage/kde-base/krdc-4.4.5/work/krdc-4.4.5/krdc/main.cpp:103

Created attachment 51725 [details]
New crash information added by DrKonqi

I can reproduce it now:
1. define a RDP connection with an invalid username/password to a server, which is hwoever reachable over port 3389
2. open another working RDP connection
3. close the window of the 1st connection
4. enjoy

Please try to reproduce this issue with KRDC from KDE SC 4.5.

*** This bug has been marked as a duplicate of bug 242586 ***