Some cocos2d-x games published their HD version for ipad. But I find some of them have a same bug: flickers on ipad2.
There are 2 examples. ( the authors may fix this bug in the next version )
Link Link 2 HD
Fisheries Crisis HD
Regarding to cocos2d-iphone's post "cocos2d and iPad 2" http://www.cocos2d-iphone.org/archives/1430, cocos2d-x games have the same problem. RicardoQuesada believed it's a iPad2 bug, no cocos2d.
As the default setting, cocos2d-x uses 3D projection with a depth buffer, in CCDirector::setGLDefaultValues()
So for ipad2 games, don't forget to invoke
Either one is OK. After this modification, please re-test your whole game. setDepthTest may affect some effects, transitions, and tilemap z order behaviours