Ever since 13w39b leaves have had no shade

Ever since snapshot 13w39c leaves have no shade and are not responding to the biomes there placed in, I was on skype and asking my freinds if this was happening to them and they said "No"! My smooth lighting is on maximum
and my graphics are on fancy? Why is this happening? MOJANG PLEASE FIX

(This happens in EVERY biome)

Youtube: Minecraft Keagan