I may have found a bug while playing with the Cloud Generator add-on in the latest development build. As you can see from the attached screnshots, both the Rendered 3D View and during rendering with the latest build the clould is not correctly rendered or displayed in rendered mode while opening the same scene in Blender 2.77a official build it works as expected. I hope that someone could find the source of this issue.
Windows 7 Pro 64bit w/SP1, 8GB RAM, GTX360M (1GB VRAM)
Broken: 2.77.1 (Hash: de3181b) 64bit zipped
Worked: 2.77a 64bit (Hash: abf6f08) official stable release (ZIP version)
Blender 2.77.1 (wrong)
Blender 2.77a (correct)