Displacement map ugly problem on edges

[Andrew07]

Hi: ( Working on Maya )

I am creating a stone text logo and I am stuck with a problem.
After creating the letters I use a stone texture as displacement map to get the detail of the stone.

Everything looks great but on borders the displacement goes wrong.
I map the letters with automatic 6 planes mapping, I use aproximation editor. I think everything is ok but not. The edges look like if the had not a nice mapping and if I animate and rotate the letter, the rest of displacement works well but edges don't seem to follow the movement. As if they had not mapping coordinates.

I even try to eliminate the bevels on edges, having a hard edge and the problem persists.
I even try to create a simple cube and I apply this stone displacement and the edges looks as ugly as I am telling you.

I am really stuck with this.
Anyone can understand what I am trying to explain ???

Thanks to all of you

[thee]

please delete the other post of andrew in cg chat, and afterwards this one too. Thanks
Thee