Is there anyway to know exactly what the LoS from a square you're potentially going to move to? It's hard to tell exactly before you move and after you move is way too late.
Ctrl-clicking the square you want to check highlights all visable squares from there. If that doesn't work, it may have been Ctrl-right click.
Also, I just the a tip about mousing over a monster highlights their line of sight in green. Also helps you figure out where you want to move to.
If we ctrl + right click a square with a terrain attachment, we can't see its line of sight. Is it possible to change this?
Maybe the terrain attachments could be made a little smaller to facilitate the empty-area-clicking? It would also make it look more like a game board with loose terrain tiles on top of it.