press back button android when change scene close the game

Question

i have 3 scenes
scene : mainmenu , levelselect , loadlevel

when i press back button on ..
mainmenu -> game exit
levelselect -> back to mainmenu
loadlevel -> levelselect

when i press back button on transition scene the game exit
transition from mainmenu to levelselect -> game exit
transition from levelselect to loadlevel -> game exit

i don't know what happend in here.

sorry if repost

Answer 1

I assume when you mean "scenes" is your activities and "press back button" is your physical back button. Anyway, why dont you try to override your "physical" back button:

@Override
public void onBackPressed() {

                Intent i = new Intent(Activity.this,
                        OtherActivity.class);
                //set this flag to avoid undesired transictions between activities
                i.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
                startActivity(i);

    }

Answer 2

i just found the answer
this error happend because bug of unity 4.3
override function backPress will not work
thx for your time