public class SplashActivity extends FragmentActivity {


    private DirectionalViewPager mDirectionalViewPager;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        mDirectionalViewPager = (DirectionalViewPager) findViewById(R.id.pager);
        mDirectionalViewPager.setAdapter(new SplashFragmentAdapter(
                getSupportFragmentManager()));
        mDirectionalViewPager.setOrientation(DirectionalViewPager.VERTICAL);
        // 加上这句应该就能解决了，不行可以看看这个链接 http://stackoverflow.com/questions/12121099/unable-to-call-activity-from-fragmentactivity
        mDirectionalViewPager.setSaveEnabled(false);


    }
}

at com.directionalviewpager.DirectionalViewPager.onSaveInstanceState(DirectionalViewPager.java:454)