I have successfully set up tabs in the Action Bar using the following example from Google themselves at http://developer.android.com/resources/samples/ApiDemos/src/com/example/a
Ok, so this answer assumes you want to wipe each tabs back history every time you swap tabs. What I mean by that is Tab 1 starts on frag 1, then you click and change it to frag 2. If you select Tab 2, you will be undoing the history of Tab 1 and next time you click Tab 1 you will be back to frag 1.
With that said here is the solution: Replace your onTabUnselected with the below
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
//this segment removes the back history of everything in the tab you are leaving so when you click on the tab again you go back to a fresh start
FragmentManager man = mActivity.getFragmentManager();
if(man.getBackStackEntryCount()>0) //this check is required to prevent null point exceptions when clicking off of a tab with no history
man.popBackStack(man.getBackStackEntryAt(0).getName(), FragmentManager.POP_BACK_STACK_INCLUSIVE); //this pops the stack back to index 0 so you can then detach and then later attach your initial fragment
//also it should be noted that if you do popbackstackimmediate here instead of just popbackstack you will see a flash as the gui changes back to the first fragment when the code executes
//end
ft.detach(mFragment);
}
}