Version:            (using KDE 4.3.4)
OS:                Linux
Installed from:    Debian testing/unstable Packages

Some events in Kopete do not use the notification framework (as used for example by incoming messages).  Instead they show a popup that disappears after a moment.

I noticed this at least when I got disconnected from a Jabber server and believe the following is the code responsible for this:

  kdenetwork-4.3.4/kopete/protocols/jabber/jabberaccount.cpp:

      if(!errorText.isEmpty()) {
        if (!additionalErrMsg.isEmpty()) {
            KPassivePopup::message( i18n("Connection problem with Jabber server %1", server),
                                    QString ("%1\n%2").arg(errorText).arg(additionalErrMsg),
                                    Kopete::UI::Global::mainWidget() );
        } else {
            KPassivePopup::message( i18n("Connection problem with Jabber server %1", server),
                                    errorText,
                                    Kopete::UI::Global::mainWidget() );
        }
    }

At least the message looks similar (it disappears too fast to be sure) and the screenshot for KPassivePopup in the API documentation looks similar.