Problem with mouse events over pg plots in taurus guis

The mouse events (right click) in the pyqtgraph.PlotWidget seem do not work when the PlotWidget is part of a TaurusGui.

You can reproduce the bug with this snippet:

import sys
from taurus.external.qt import Qt
import pyqtgraph as pg


def qapp():
    app = Qt.QApplication(sys.argv)
    mainWin = Qt.QMainWindow()
    plot = pg.PlotWidget()
    dock = Qt.QDockWidget('Plot', None)
    dock.setWidget(plot)
    mainWin.addDockWidget(Qt.Qt.TopDockWidgetArea, dock)
    mainWin.show()
    sys.exit( app.exec_() )


def tapp():
    from taurus.qt.qtgui.application import TaurusApplication
    from taurus.qt.qtgui.taurusgui import TaurusGui
    app = TaurusApplication()
    mainWin = TaurusGui()
    plot = pg.PlotWidget()
    dock = Qt.QDockWidget('Plot', None)
    dock.setWidget(plot)
    mainWin.addDockWidget(Qt.Qt.TopDockWidgetArea, dock)
    mainWin.show()
    sys.exit( app.exec_() )


if __name__ == "__main__":
    # qapp() # Works
    tapp()   # Does not work