It's definitely possible, having a sturdier frame will definitely prevent flexing, which would result in cracking the screen, but unless it's some piece of junk phone, I just don't see it making a huge difference at the smaller screen size. As the screens get larger, a more rigid frame will probably become more and more important when abusing the phone or putting it through stress. Then again, I don't imagine the majority are putting their $300(600) phones through the kind of stress that we're talking about. I mean the Razr has a metal frame and a kevlar back and I've seen more people complain on their forums of shattered screens than any other device thus far in the past year. So it may not be the frame strength as much as it being so thin that the frame is being warped due to it's thinness, not the material being used.