Bukkit

I noticed a number of people attempting to manually populate a world with ore veins. Initially the manual command was meant to run on "virgin" worlds, and even when some areas were populated, that wouldn't cause problems as COV used to properly clean those areas up before repopulating. Since the plugin evolved, allowing various kind of impurities to be spawned, impurities that most of the times tend to blend in with the game generated ones,  the cleanup stage had to ignore these. This is now causing a mess when attempting to execute this command multiple times. A simple and fast solution would be for it to ignore already generated areas.