Yeh the guide isnt worth shit, the nests just spawn random around the swamp didnt find any in any of the caves,spent ages going back and forth to the caves in case they appeared at a certain time and in the end i found they by random chance while doing other stuff.

The nests are in the same place, I've played the game finish 2 times, and the nest are always there. The one at the waterfall you have to go closer to the tree you see on the map close to the ruins. So if I remember right (can't see the map atm) it is a little NE of the waterfall.

Hope this helps

http://www.youtube.com/watch?v=yfmcFF3VoxE

hope this helps.....u can also buy grapeshots from cerdic