Ok, now I realise this is perhaps slightly more suited to "bug Reports", but I figured the solution would probably be best solved by someone who understands light mapping better than I, so here goes.
Sometimes when I place a large entity into the level, such as the drop ship, or landscape pack entities, they don't lightmap propperly. If I place a bulb half way ove the mountain for example, it does not light an area of the mountain, it just stays dark.
Same goes with the drop ship and bridge entities I have created, they don't lightmap at all, they're fine with lightmaps turned off, but as soon as a turn it on, they remain dark, even if there's a light marker right next to them.
I don't think this is a bug like the "black entities" bug, as the object is still visible, infact if I crank the amb up a bit I can see it, but if I make the amb low, and place a light next to the entity, it remains unlit.
Is this just a size issue? I mean the dropship is only 786kb, and it's UVd propperly. Am I just being a retard? Somebody help, without fixing this landscape pack 2 was a waste of money!