Displacement Modifier ?

[markf]

I have a stone material applied to some geometry. I have a UVW box maping modifier applied. I have a Vray Displacement modigfier applied. I have set the tiling on the diffuse map to values .37, .75. I made a black and white bump map out of the diffuse texture and have it in the texture slot of the Vray Displacement. Using 2D mapping. I instanced the displacement map into the material editor and set the tiling to .37, .75.

 

It doesn't match up with the diffuse map correctly. I can't figure out what I'm doing wrong. Is what I'm doing with the tiling not possible in Vray Displacement modifier?

 

Any help is much appreciated