I have a lot of env_sprite entities which when watched from certain angles don't render at all or are rendered rotated. See the video:
http://youtu.be/7vlm4OBNhnE

Using mat_wireframe 3 I noticed that the plane of sprite is incorrectly calculated. It should always face the player because "vp_parallel" setting is set in material settings:
"$spriteorientation" "vp_parallel"
But instead of facing player it faces something other and is not rendered at all sometimes.

The fun thing is that I tested the same sprites on the small test level and they work fine in it and always face player.
What is it related to and how do I fix sprites in my map?