How to tell when a new world has finished generating?

[GeckoThePecko]

I have a method that runs when the NeighborNotifyEvent is fired and it basically checks for a cobblestone generator (water + lava) and changes the resulting cobblestone to sand instead. Everything works fine, minus the fact that when you try to generate a new world, the game crashes because of a StackOverflow Exception. I assume this is because there are so many collisions of water and lava underground and the game can't handle it? What would be the best way to prevent the method from running while the world is being generated?

[Cadiboo]

Please post your log and code