Beer Science

This weekend, I anadvertently performed an experiment with bottled beer. I happen to have a large surplus of bottled beer at the moment. While I'm bravely making headway, some of the beer has been forced to sit out on top of the refrigerator. Thus, it has been exposed to temperatures below the freezing point of water. Most of the beers were unaffected by the chill temperatures. Strangely, though, bottles of Miller Genuine Draft were half frozen, while bottles of MGD Light in the same six-pack holder were unaffected. What gives?

Everything I can think of about Light beer should indicate that it freezes at a higher temperature than regular beer. Regular beer has more alcohol, more carbohydrates, and so on. Yet, the MDG froze first. Anyone have any theories?