shadows and layers

it always seems when I just get to the point when things are going good that i notice things that aren't good. Here's todays

shadows only show on layer 0 (possibly 1 and 2, i don't really know) and for this point, bats that fly above these layers don't produce shadows on them. why is this important?? in one of my levels, there is a staircase that goes across a part you can walk under as well, all on the same screen. There's a pit warp on the stairs, and it sends you full screenily to the above part. The bats transfer w/ the FSW, and their shadows magically appear from under the walkway to above it. When i walk back down the stairs, the shadows magically disappear.

that's all i'm good for.