uimodalpresentationpagesheet goes under the status bar

Question

In the FirstView by pressing a button, SecondView is presented in UIModalPresentationPageSheet

secondVC.modalPresentationStyle=UIModalPresentationPageSheet;

The SecondView appears fine (its upper bound is next to the status bar) #1. Then in the SecondView,by pressing a button, ThirdView is presented in this way:

    thirdVC.modalPresentationStyle=UIModalPresentationFullScreen; 
    //I tried also commenting it, but the error occurs anyway.

In this ThirdView there is an UINavigationBar added in the xib and it is partially under the status bar (first problem) #2. When from the ThirdView user goes to the SecondView, it doesn't appear fine anymore: its upper bound this time is partially under the status bar #3.

How I can resolve it?

(it's an iPad app) (also in the SecondView there is an UINavigationBar added in the xib)

Edit: Screenshots !#1 1

!#2 2

!#3 3