IPhone : UIBarButton title text not showing up on modal view controller when "Button Shapes" accessibility feature is turned on

When I try to modally present a view controller the bar buttons on either side of the title of navigation bar is not showing up. This happens only when the "Buttons Shapes" accessibility feature is turned on under iPhone settings menu. It just shows up a plain blank white space. But when I try to tap the button I could see the button's presence and the button shape drawn around it.

Could some help and point me in right direction ?

Thanks