HSplit groups conflicts with mayavi toolbar buttons (pyside)

The example `mayavi/examples/mayavi/interactive/mayavi_traits_ui.py` fails with pyside when clicking on one of the toolbar buttons with the exception

Traceback (most recent call last):
File "c:\users\pietro berkes\devel\ets\pyface\pyface\ui\qt4\action\action_item
.py", line 352, in _qt4_on_triggered
print 'control', self.control.isChecked()
RuntimeError: Internal C++ object (PySide.QtGui.QAction) already deleted.

The problem can be solved by changing the HSplit group to an HGroup in the example.

The code laying out the splitters seems to be deleting those QActions somehow...