SkyX ground atmospheric light absorption pass problem.

Hi,

I Think this forum not too active , but i hope...

I use Skyx modified version from by Max98 Rigs of Road, http://www.ogre3d.org/addonforums/viewtopic.php?f=20&t=30381 (But the problem same as original skyx 0.4 version...)
If i use atmospheric light absorption pass on terrain material everything works fine, but i get some color square on the ground.
Running on Ogre 1.10 and the problem same as dx and gl.

Any idea what is this?

far image:


close-up image:


Thank you any advice