I'm trying to do some really simple, on-the-fly editing of a regular random map that the game created. I'm trying to tweak the resources of each region manually by simply plopping down the terrain bonus's (i.e. coal, oil, uranium, spices, corn, etc.) manually once in-game. I can't seem to do this for all but a very limited number of bonus's. I can plop down cows on their proper terrain type, for example, but not oil or coal or iron. I've looked through the CIV4BonusInfos.xml file and checked which terrain types are required for the bonus's, and I'm pretty sure I'm reading it correctly, but yet I still can't plop down these bonus's. What's the deal? Am I missing something obvious?