Android and ActionBarCompat: how to change visibility of actions at runtime on pre-ICS devices?

I have an Activity that extends ActionBarActivity taken from the ActionBarCompat code sample and I'm trying to show/hide menu items (actions) at runtime.

I've tried using setVisible() on the MenuItem and works for ICS, but in pre-ICS it only change visibility of menu items (menu button press) whereas the ActionBar doesn't get notified of menu changes.

Any solution? Thanks in advance!