Starved for Food, Zimbabwe Rejects U.S. Biotech Corn (washingtonpost.com). Basically; if Zimbabwe takes the genetically-modifed corn as part of food aid, they risk someone planting the corn and ending up with modified corn being grown... which then can't be exported. So, they may eat today but be unable to eat or make a living tomorrow. It's a hell of a choice; saying no to the corn will take serious guts - but what is the greater good here? Feed someone once today vs. allowing them to be independent tomorrow..?
Serious ethical issues are clashing on this one... it could definitely be taken as a hostile imposition of US values onto another nation. Zimbabwe has been trying to stay natural for years; for just this sort of reason. But how the hell do you tell a subsistence farmer in Zimbabwe that an American company owns the patent on their corn, so they can't sell it and it's illegal to grow it?
It seems the only viable solution will be to mill the corn before distribution, but all of a sudden it becomes expensive "aid", since processing is not covered by the aid package.