Terrain scale and positioning

I'm trying out the terrain in TGE 1.5 in an existing (rather elaborate) map. What I'd like to do is resize and reposition the terrain and put it in just the right place. However, chaning the position values in the block don't seem to affect where the engine puts the terrain?

I've done a _lot_ of searching for answers, but I haven't found an explanation. Is it a bug?

Lee