Not only are gringos not allowed to actually own property (99-year lease with a Mexican managing partner is the best you can do), but in cruel reality, a Mexican land title is nigh on worthless even to a Mexican. When you get right down to it, no one south of the border actually knows who owns what. There is no clear title to anything. It is mired in a quasi-feudal arrangement, where crooked judges delight in awarding, un-awarding, and re-awarding property to a succession of litigants who maintain rights by force and bribery. Probably sounds stupid to Americans, but where the rubber meets the road, that's the deal. The system is: ain't no system. Fee Simple? Too simple for Mexico, apparently.
Maybe when the Iraqi Constitutional Convention is done, they can fax a copy of their work to Vicente Fox and the Oligarchs. Just having a clear legal code would open up the economic potential of our neighbour to the south in a big way.