I was setting "sun_light" to zero right before loading level in main script, and after loading level, I was calling function, which handles weather (fog, lods etc). I've made it long time ago, and I always just include it in my projects, I've completely forgot that I've set "sun_light" to 100 in that function. So, problem was simple as hell (problem was in me, I'm too inattentive). About dynamic lights, I think they pass through walls if you create them during run-time (calculating lights and so on, would be slow, if they don't pass), but I might be wrong.