Android : Android ActionBar Tabs with FragmentPagerAdapter Class - saving the last tab selected when reloading activity

I am developing an app which is using ActionBar.NAVIGATION_MODE_TABS and a separate FragmentPagerAdapter class in order to swipe through 5 different screens. On these screens there are buttons you can press to load a new activity, and then go back to the MainActivity when done. My problem is, every time you go back and reload the MainActivity it defaults back to the first tab (0).

I have tried many different solutions to try and get the previously selected tab to load when the activity is reloaded including SharedPreferences, saving instance state and trying to force the FragmentPagerAdapter class to load a certain fragment when called - but something keeps overriding it and it always goes back to the first tab (0) without fail. I would be really grateful for any possible solutions to this.

Code as follows:

public class MainActivity extends FragmentActivity implements TabListener {

ActionBar tabBar;
ViewPager viewPager;

@Override
protected void onCreate(Bundle currenttab) {
    super.onCreate(currenttab);
    setContentView(R.layout.activity_main);

    // Sets up view pager
    viewPager = (ViewPager) findViewById(R.id.pager);
    viewPager.setCurrentItem(0);
    viewPager.setAdapter(new MainAdapter(getSupportFragmentManager()));
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageSelected(int currenttab) {
            tabBar.setSelectedNavigationItem(currenttab);
        }

        @Override
        public void onPageScrolled(int currenttab, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int currenttab) {
        }

    });

    // Adds tabs to action bar
    tabBar = getActionBar();
    tabBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    ActionBar.Tab tab1 = tabBar.newTab();
    tab1.setIcon(R.drawable.action);
    tab1.setTabListener(this);

    ActionBar.Tab tab2 = tabBar.newTab();
    tab2.setIcon(R.drawable.jobs);
    tab2.setTabListener(this);

    ActionBar.Tab tab3 = tabBar.newTab();
    tab3.setIcon(R.drawable.historic);
    tab3.setTabListener(this);

    ActionBar.Tab tab4 = tabBar.newTab();
    tab4.setIcon(R.drawable.breeds);
    tab4.setTabListener(this);

    ActionBar.Tab tab5 = tabBar.newTab();
    tab5.setIcon(R.drawable.special);
    tab5.setTabListener(this);

    tabBar.addTab(tab1);
    tabBar.addTab(tab2);
    tabBar.addTab(tab3);
    tabBar.addTab(tab4);
    tabBar.addTab(tab5);
}

// Action bar methods
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    viewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {

}

@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}

// Class to deal with swipe function

class MainAdapter extends FragmentPagerAdapter {
public MainAdapter(FragmentManager fm) {
    super(fm);
}


@Override
public Fragment getItem(int currenttab) {
    // TODO Auto-generated method stub
    Fragment fragment = null;
    if (currenttab == 0) {
        fragment = new FragmentAction();
    }
    if (currenttab == 1) {
        fragment = new FragmentJobs();
    }
    if (currenttab == 2) {
        fragment = new FragmentHistory();
    }
    if (currenttab == 3) {
        fragment = new FragmentBreeds();
    }
    if (currenttab == 4) {
        fragment = new FragmentSpecial();
    }
    return fragment;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return 5;
}
}