ActionBarSherlock4.1でActivituUnitTestCaseがエラーになる件

gistfile1.java

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.test.ActivityUnitTestCase;

public class MainActivityUnitTest extends ActivityUnitTestCase<MainActivity> {

    private Intent _startIntent;

    public MainActivityUnitTest() {
        super(MainActivity.class);
    }

    @Override
    protected void setUp() throws Exception {
        super.setUp();

        Context targetContext = getInstrumentation().getTargetContext();

        //Set your theme
        targetContext.setTheme(R.style.AppTheme);

        setActivityContext(targetContext);

        _startIntent = new Intent(Intent.ACTION_MAIN);
    }

    public void testPreconditions() {
        startActivity(_startIntent, null, null);
        assertNotNull(getActivity());
    }
}

Manifestでtheme設定してる場合。
Activity#onCreate()でsetTheme()してる場合は関係ないです。