Fragments, how do they work?

notWorkingWell.java

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
        FragmentManager manager = getFragmentManager();

        FragmentTransaction fts = manager
                .beginTransaction();

        // lazy instantiation for the win
        if (tab.getTag() == "PoiListFragment") {

            if (lFrag == null) {
                lFrag = new PoiListFragment();
            }
            fts.replace(R.id.frameContainer, lFrag, "HTL");
            fts.commit();
        } else {
            fts.replace(R.id.frameContainer, mMapFragment, "MF");
            fts.commit();
            manager.executePendingTransactions();

            if (mMapFragment != null) {
                myMap = mMapFragment.getMap();
                if (myMap != null) {
                    myMap.setMyLocationEnabled(true);
                } else {
                    Toast.makeText(this, "Error - Map was null!!",
                            Toast.LENGTH_SHORT).show();
                }
            } else {
                Toast.makeText(this, "Error - Map Fragment was null!!",
                        Toast.LENGTH_SHORT).show();
            }
            if (isGooglePlayServicesAvailable()) {
                mLocationClient.connect();
            }
        }
    }

worksWell.Java

//in onCreate, I call this
private void makeFragments() {
        mMapFragment = new MapFragment();
        if (lFrag == null) {
            lFrag = new PoiListFragment();
            lFrag.setRetainInstance(true);
        }
    }
/////////////////////////////////////////////

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
        FragmentManager manager = getFragmentManager();

        FragmentTransaction fts = manager
                .beginTransaction();

        // lazy instantiation for the win
        if (tab.getTag() == "PoiListFragment") {

            if (mMapFragment.isAdded()) {
                fts.hide(mMapFragment);
                fts.show(lFrag);
            } else {
                lFrag = new PoiListFragment();
                fts.add(R.id.frameContainer, lFrag, "HTL");
            }

            fts.commit();
        } else {


            mMapFragment.setRetainInstance(true);
            fts.hide(lFrag);
            if (mMapFragment.isAdded()) {
                fts.show(mMapFragment);
            } else {
                fts.add(R.id.frameContainer, mMapFragment, "MF");
            }


            fts.commit();
            manager.executePendingTransactions();
            // mMapFragment = ((SupportMapFragment)
            // getSupportFragmentManager().findFragmentById(R.id.map));
            if (mMapFragment != null) {
                myMap = mMapFragment.getMap();
                if (myMap != null) {

                    myMap.setMyLocationEnabled(true);
                } else {
                    Toast.makeText(this, "Error - Map was null!!",
                            Toast.LENGTH_SHORT).show();
                }
            } else {
                Toast.makeText(this, "Error - Map Fragment was null!!",
                        Toast.LENGTH_SHORT).show();
            }
            if (isGooglePlayServicesAvailable()) {
//				Toast.makeText(this, "Connected to location client",
//						Toast.LENGTH_SHORT).show();

                mLocationClient.connect();
            }

        }

    }