Well, its kind of your coding error/the way NDB and BlitzTerrain choose to work
This is because Advanced Terrain uses limbs and Blitzterrain uses objects.
Limb positions are stored inside the geometry data of the object but the objects position isnt.
So when NDB looks at the object, it takes the geometry data to make the body, but as it doesnt know its actual position. It positions the body to 0,0,0.
What you have to do is after you create the body use this:
ndb set body position body,object position x(phyobjnum), (same for y and z)
Then your done!
NDB really should do this automatically.