Missing label ttf on WP8 cocos2d-x 3.2

Hi everybody!

I’m compiling my game on WP8 and i have a problem with label ttf (Label::createWithTTF), everything works fine when first displayed,but after a few time i open diffirent popup, my popup missing label (see screenshot).

Can anybody tell me the solution? Sorry for my bad English =_=!

and poup missing label