I'm using the scenario editor and I've noticed the default scenario has a "spawn randomly: ship chunk x3" parameter to it. If I try to add this manually to another scenario, "Ship Chunk" is no where to be found on the list of items. I can make it spawn components just fine, but that just isn't as fun. I wanted to make a desert full of crashed ships for my poor colonists to scavenge, but it's rather difficult to setup now. I have to edit the default scenario to do it.
I've had the same problem, and I wish they would fix this in a hot patch or something. It doesn't help that the standard crash landing scenario waves the bug in your face.