Connecting to a postgreSQL database with windows CE over wi-fi; failing gracefully

Hello,

I'm developing a PostgreSQL application for Windows CE 5 on a PDT/ PDA
in C++/Qt, using Hiroshi Saito's libpq port for that platform. Since
the connection is established over wi-fi, and wi-fi connectivity is
often flaky, I feel that I have to "fail gracefully" to as great an
extent as possible. The following utility function,
VerifyDbConnection(), is called before every piece of database work:

void MainInterface::VerifyDbConnection()
{
    if (PQstatus(conn) != CONNECTION_OK)
    {
        for(;;)
        {
            PQreset(conn);
            if(PQstatus(conn) == CONNECTION_OK)
                return;

            QMessageBox msgbox_connection_lost;
            msgbox_connection_lost.setText("Connection to the database is lost,
and cannot be re-established. "
                "This may be due to the fact that you're too far away from the
Wi-fi access point, or because "
                "the backoffice computer is turned off, or it may be a low level
connectivity problem." );
            QPushButton* retry_button =
msgbox_connection_lost.addButton(tr("Reconnect"),
QMessageBox::ActionRole);
            QPushButton* exit_button =
msgbox_connection_lost.addButton(tr("Exit"), QMessageBox::ActionRole);
            msgbox_connection_lost.setWindowTitle("Connection lost");
            msgbox_connection_lost.exec();

            if(msgbox_connection_lost.clickedButton() == retry_button)
            {
                continue;
            }
            else if(msgbox_connection_lost.clickedButton() == exit_button)
            {
                exit(0);
                return;
            }
        }
    }

}

This seemed to work fine initially; I'd abruptly stop the database
server, and I would see a messagebox informing me of a connectivity
problem. Then, I'd start the server, click the retry button, and have
connectivity restored. However, when I walk out of range of the wi-fi
access point, which is the probable cause of losing connectivity in
the real world, my program crashes without displaying an error message
(I would expect to see a visual C++ runtime error message).

Can someone suggest a reason for this, or a workaround?

Regards,
Peter Geoghegan