You might be right but I cant be certain of this since I don't usually work with procedural terrains.  However, I would add this:  make sure that the texture material you apply to the procedural isn't causing the terrain to change its shape.  Sometimes I have experienced my terrains to really change their shape when I apply certain materials.  Depending on the material, changing from object standard to object world and some others, can alter the topography of the terrain. 

Hope this helps

G&C