My iPhone 5 has the same problem. Yes it is a PROBLEM. Not on my iPhone 4 or any iPhones had in the past. Not in any camera I ever had. This is not lens flare or finging. I like lense flare. Anybody calling BS on here doesn't have an iPhone 5.
This issue happens regardless of shooting into light. For Apple to say it is normal is not cool. If this is normal your new product sucks. This along with the rattle in the power button, and the fact that I have to buy an adapter or all new accessories double sucks.
I had used my iPhone as my main camera in the past because it does take decent pictures and is convinient. I have knowledge of photography and know how to use a camera so don't try to tell me I am doing something wrong.
Shame on you Apple. Recall!