Action bar appears on some devices and not others
<p>I have written an app which has an action bar at the top.</p>

<p>The app works fine on my Galaxy SII (Android 4.0.4) and I see the action bar, but on my Galaxy tab (Android 3.1), the action bar does not appear - though everything else works fine.</p>

<p>I don't know whether its just the case that 3.1 does not support it or I have a bug in my code. And if its just that 3.1 doesn't support it, how come it didn't crash?</p>
