How can I Prevent Holes in smooth Terrain

[SelDraken]

I am using Perlin Noise to generate terrain.
When the surface of the terrain is using Full Opacity (value of 1) for the top layer of voxels, I have no issues.

(unless that one little dark spot is a hole and I cant tell)

However, if I use a partial voxel value, for the top layer, it get what appear to be random holes

Any idea what might cause this?
Thanks

[SelDraken]

I found my issue, apparently when getting the noise for a specific voxel location, I was clamping my coordinates to a grid, and so on occasion an x or z would be 0, returning a noise result of 0, leaving a hole.

I ended up adding .5 to the x and z in my noise inputs