I was testing on my iphone 4:
I work lettebox 960x640 scale
I work letterbox 660x440 scale
But of course I have no iphone 5 to see if it works well ... I have the entire project with 660x440 and I do not want to change all the layouts and raise the size of all images.
About what you mention, it will see the black edges and boxed the game ... not a little creepy?
I'm going crazy, I've tried everything, but I have only a cell phone in the other do not know if it works :(
another solution may be to put the maximum size resolution of the iphone 5 and put crop? pff <img src="smileys/smiley18.gif" border="0" align="middle" />