New at Height map editing

[TheOutlander]

So I lowered a section of raised ground so that it is now flat using the heightmap editor, but ingame there is this grey blob where and the exact shape of the ground I flattened.

http://i52.tinypic.com/119plwh.jpg

How do I get rid of it?

 

 

EDIT: Nevermind, I killed it via "World > World LOD > select worldspace > Generate Terrain textures"

Edited September 5, 2011 by TheOutlander