Bug 198508 seems to be related. Does the app always crash when you perform that action ? Thanks

can't tell if that bug is related. the debug output looks different but the behaviour seems similar. 
I can't really remember when it started to crash as I don't use kgpg that often but update often on debian/sid. 

yes, it always crashes when I try to open it via the trayicon.  
btw, is there another way to try to get to kgpg's main window? if would work it might help find the issue and be a workaround too

if you need more data/info of course feel free to ask tho I might add I am not a dev but maybe an experienced user.

good luck, thanks for the effort and hope I could help :)

> yes, it always crashes when I try to open it via the trayicon.
> btw, is there another way to try to get to kgpg's main window? if would
>  work it might help find the issue and be a workaround too

"kgpg -k"

> if you need more data/info of course feel free to ask tho I might add I am
>  not a dev but maybe an experienced user.

At the moment I have no idea what happens at all. The stack trace does not 
show anything KGpg related. You clicked the systray and he tries to bring up a 
window which fails.

here is what I get from "kgpg -k". the main windows does not come up and the
crashhandler-thingy is invoked (trace copied & pasted from there). 

~$ kgpg -k
<unknown program name>(22632)/: Communication problem with  "kgpg" , it probably crashed.
Error message was:  "org.freedesktop.DBus.Error.NoReply" : " "Message did not receive a reply (timeout by message bus)" "


Application that crashed: kgpg
Version of the application: 2.2.1
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-0.slh.3-sidux-686 i686
Distribution: Debian GNU/Linux unstable (sid)

What I was doing when the application crashed:
this what happens when I run

~$ kgpg -k
<unknown program name>(22632)/: Communication problem with  "kgpg" , it probably crashed.
Error message was:  "org.freedesktop.DBus.Error.NoReply" : " "Message did not receive a reply (timeout by message bus)" "


 -- Backtrace:
Application: KGpg (kgpg), signal: Segmentation fault
[KCrash Handler]
#6  QModelIndex (this=0x9088fb8, child=...) at ../../include/QtCore/../../src/corelib/kernel/qabstractitemmodel.h:65
#7  QSortFilterProxyModel::parent (this=0x9088fb8, child=...) at itemviews/qsortfilterproxymodel.cpp:1552
#8  0xb75723d8 in QModelIndex::parent (this=0x9095028, index=...) at ../../include/QtCore/../../src/corelib/kernel/qabstractitemmodel.h:369
#9  QTreeView::indexRowSizeHint (this=0x9095028, index=...) at itemviews/qtreeview.cpp:2764
#10 0xb7572b12 in QTreeViewPrivate::itemHeight (this=0x9097268, item=1) at itemviews/qtreeview.cpp:3207
#11 0xb7572dd0 in QTreeViewPrivate::updateScrollBars (this=0x9097268) at itemviews/qtreeview.cpp:3459
#12 0xb7573152 in QTreeView::updateGeometries (this=0x9095028) at itemviews/qtreeview.cpp:2693
#13 0xb752e864 in QAbstractItemView::resizeEvent (this=0x9095028, event=0xbfc1c064) at itemviews/qabstractitemview.cpp:2186
#14 0xb704658e in QWidget::event (this=0x9095028, event=0xbfc1c064) at kernel/qwidget.cpp:7695
#15 0xb73ecf53 in QFrame::event (this=0x9095028, e=0xbfc1c064) at widgets/qframe.cpp:559
#16 0xb748bf6f in QAbstractScrollArea::viewportEvent (this=0x9095028, e=0x2a746551) at widgets/qabstractscrollarea.cpp:962
#17 0xb753d127 in QAbstractItemView::viewportEvent (this=0x9095028, event=0xbfc1c064) at itemviews/qabstractitemview.cpp:1476
#18 0xb7577f26 in QTreeView::viewportEvent (this=0x9095028, event=0xbfc1c064) at itemviews/qtreeview.cpp:1266
#19 0xb748e545 in QAbstractScrollAreaPrivate::viewportEvent (this=0x9098878, o=0x9097720, e=0xbfc1c064) at widgets/qabstractscrollarea_p.h:100
#20 QAbstractScrollAreaFilter::eventFilter (this=0x9098878, o=0x9097720, e=0xbfc1c064) at widgets/qabstractscrollarea_p.h:111
#21 0xb6b07bfa in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x8eed488, receiver=0x9097720, event=0xbfc1c064) at kernel/qcoreapplication.cpp:726
#22 0xb6ff07ec in QApplicationPrivate::notify_helper (this=0x8eed488, receiver=0x9097720, e=0xbfc1c064) at kernel/qapplication.cpp:4052
#23 0xb6ff8a52 in QApplication::notify (this=0x8edf8e0, receiver=0x9097720, e=0xbfc1c064) at kernel/qapplication.cpp:4021
#24 0xb7a394ad in KApplication::notify (this=0x8edf8e0, receiver=0x9097720, event=0xbfc1c064) at ../../kdeui/kernel/kapplication.cpp:302
#25 0xb6b089cb in QCoreApplication::notifyInternal (this=0x8edf8e0, receiver=0x9097720, event=0xbfc1c064) at kernel/qcoreapplication.cpp:610
#26 0xb7044ebc in QCoreApplication::sendEvent (this=0x9097738, recursive=false, disableUpdates=false) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#27 QWidgetPrivate::sendPendingMoveAndResizeEvents (this=0x9097738, recursive=false, disableUpdates=false) at kernel/qwidget.cpp:6646
#28 0xb704bb16 in QWidgetPrivate::show_helper (this=0x9097738) at kernel/qwidget.cpp:6697
#29 0xb704c22b in QWidget::setVisible (this=0x9097720, visible=true) at kernel/qwidget.cpp:6975
#30 0xb704c008 in QWidget::show (this=0x9097268, spontaneous=false) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:473
#31 QWidgetPrivate::showChildren (this=0x9097268, spontaneous=false) at kernel/qwidget.cpp:7063
#32 0xb704bb41 in QWidgetPrivate::show_helper (this=0x9097268) at kernel/qwidget.cpp:6703
#33 0xb704c22b in QWidget::setVisible (this=0x9095028, visible=true) at kernel/qwidget.cpp:6975
#34 0xb704c008 in QWidget::show (this=0x8f68be0, spontaneous=false) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:473
#35 QWidgetPrivate::showChildren (this=0x8f68be0, spontaneous=false) at kernel/qwidget.cpp:7063
#36 0xb704bb41 in QWidgetPrivate::show_helper (this=0x8f68be0) at kernel/qwidget.cpp:6703
#37 0xb704c22b in QWidget::setVisible (this=0x8ee1e48, visible=true) at kernel/qwidget.cpp:6975
#38 0x080bb436 in QWidget::show (this=0x8edf8e0) at /usr/include/qt4/QtGui/qwidget.h:473
#39 KGpgApp::newInstance (this=0x8edf8e0) at ../../kgpg/kgpg.cpp:105
#40 0xb7a40796 in KUniqueApplicationAdaptor::newInstance (this=0x8f6c370, asn_id=..., args=...) at ../../kdeui/kernel/kuniqueapplication.cpp:459
#41 0xb7a40832 in KUniqueApplicationAdaptor::qt_metacall (this=0x8f6c370, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfc1c608) at ./kuniqueapplication_p.moc:75
#42 0xb6c1fbe5 in QDBusConnectionPrivate::deliverCall (this=0x8edd780, object=0x8f6c370, msg=..., metaTypes=..., slotIdx=4) at qdbusintegrator.cpp:891
#43 0xb6c20d32 in QDBusConnectionPrivate::activateCall (this=0x8edd780, object=0x8f6c370, flags=337, msg=...) at qdbusintegrator.cpp:796
#44 0xb6c21254 in QDBusConnectionPrivate::activateObject (this=0x8edd780, node=..., msg=..., pathStartPos=16) at qdbusintegrator.cpp:1370
#45 0xb6c2173a in QDBusActivateObjectEvent::placeMetaCall (this=0x8f684a8) at qdbusintegrator.cpp:1464
#46 0xb6b18e10 in QObject::event (this=0x8edf8e0, e=0x8f684a8) at kernel/qobject.cpp:1110
#47 0xb6b0836b in QCoreApplication::event (this=0x8edf8e0, e=0x8f684a8) at kernel/qcoreapplication.cpp:1434
#48 0xb6ff6049 in QApplication::event (this=0x8edf8e0, e=0x8f684a8) at kernel/qapplication.cpp:2317
#49 0xb6ff0814 in QApplicationPrivate::notify_helper (this=0x8eed488, receiver=0x8edf8e0, e=0x8f684a8) at kernel/qapplication.cpp:4056
#50 0xb6ff897e in QApplication::notify (this=0x8edf8e0, receiver=0x8edf8e0, e=0x8f684a8) at kernel/qapplication.cpp:3603
#51 0xb7a394ad in KApplication::notify (this=0x8edf8e0, receiver=0x8edf8e0, event=0x8f684a8) at ../../kdeui/kernel/kapplication.cpp:302
#52 0xb6b089cb in QCoreApplication::notifyInternal (this=0x8edf8e0, receiver=0x8edf8e0, event=0x8f684a8) at kernel/qcoreapplication.cpp:610
#53 0xb6b0960e in QCoreApplication::sendEvent (receiver=0x0, event_type=0, data=0x8ec7428) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#54 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x8ec7428) at kernel/qcoreapplication.cpp:1247
#55 0xb6b097ed in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#56 0xb6b33c0f in QCoreApplication::sendPostedEvents (s=0x8ee6320) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#57 postEventSourceDispatch (s=0x8ee6320) at kernel/qeventdispatcher_glib.cpp:210
#58 0xb6115e98 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#59 0xb6119623 in ?? () from /lib/libglib-2.0.so.0
#60 0xb61197a8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#61 0xb6b33858 in QEventDispatcherGlib::processEvents (this=0x8ec7178, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#62 0xb708ffd5 in QGuiEventDispatcherGlib::processEvents (this=0x8ec7178, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#63 0xb6b0701a in QEventLoop::processEvents (this=0xbfc1cf20, flags=...) at kernel/qeventloop.cpp:149
#64 0xb6b07462 in QEventLoop::exec (this=0xbfc1cf20, flags=...) at kernel/qeventloop.cpp:201
#65 0xb6b098b9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#66 0xb6ff0697 in QApplication::exec () at kernel/qapplication.cpp:3525
#67 0x080bc843 in main (argc=2, argv=0xbfc1d0f4) at ../../kgpg/main.cpp:57

Which is a crash at the very same place, just a different way to get there. That's totally weird.

Would you mind sending me your ~/.gnupg/gpg.conf, ~/.kde4/share/config/kgpgrc, and ~/.gnupg/pubring.gpg by _private_ _mail_? The kgpgrc might be in a slightly different path depending on your distribution.

*** Bug 233052 has been marked as a duplicate of this bug. ***

This is indeed a dupe of 198508 (Thanks Dario for finding this). As there is basically no KGpg code in the trace I can't help you here. Please try upgrading to KDE SC 4.4. I've never seen anything similar in 4.4 and the notification item stuff has been improved there, too.

*** This bug has been marked as a duplicate of bug 198508 ***

upgraded to KDE SC 4.4.2 and it works fine again. :)
thanks for the great work and your time