getActionBar() returns null

I'm having an odd problem. I am making an app with targetsdk 13. In my main activity's onCreate method i call `getActionBar()` to setup my actionbar. This works fine when running on the Android 3.2 emulator, but when using Android 3.0 and 3.1 the `getActionBar()` method returns null. I find this extremely odd, and i cannot see any reason why it would do so. Is this a bug with the emulators or is there something i need to do, in order to ensure that my application has an actionbar? SOLUTION: I think I've found a solution for this problem. I wasn't using the setContentView to set a layout for the activity. Instead I was using `fragmentTransaction.add(android.R.id.content, mFragment, mTag)` to add a fragment to the activity. This worked fine in 3.2, but in earlier honeycomb versions the action bar is apparently not set if you don't use the setContentView in the `onCreate()` method. So I fixed it by using the `setContentView()` method in my `onCreate()` method and just supplying it with a layout that contained an empty FrameLayout. I can still use the `fragmentTransaction.add(android.R.id.content, mFragment, mTag)` method the same way as before. It's not the prettiest fix, but it works.