Testing an iPhone application with iPad Simulator

I have developed an application for iPhone devices, the application works perfectly both in simulator and devices. Now I have tried to ru开发者_开发知识库n the application on iPad (both simulator and real iPad), the application appears but my custom carousel object is not showed... there are no error in the traces but the object is not showed in the screen, I do not know where should I look first.... any help? Have I need to take special considerations in order to develop a custom object for iPad? Thanks in advance

More data about this. I have checked the UIView.frame.size.width, on iPhone simulator the value is not zero, but on iPad simulator it is 0... I'm totally lost :(

It seems that cleaning and rebuilding resolves the problem... maybe some missing image..