EDIT: I tested my version on GZDoom 2.4.0 for 32-bit, using only SD and D2TWID, I put all my preferable settings on... And elemental is completely fine, which leads me to the thought, that the problem is caused not by SD, but by skybox pack, but I need further researches.
EDIT 2: I tested it on 64-bit version (Which is the exact version that I use), and elemental is completely fine. I guess, I should say goodbye to my skyboxes...
