PROBLEM - ALPHA ON FX_TERRAINTEX

I applied the shader fx_terraintex in a terrain, and is happening this problem of transparency:

http://upload.crazzy.com.br/show-image.php?id=a0058897f1fdeb3eeb0074cfa13d700c

Why is this happening?

The textures and their alpha channels are applied correctly.

Note: the effect works correctly on another project, only that this problem occurs.

OK, I found the problem: duplicate declaration of purpose! For those who have been through this and do not leave the problem too, is there!