nodraw brushes should in general not block the line-of-sight (afair) - but it should in this case. we have to find a working solution for every map here.
?
Strange behaviour. After all nodraw brushes represent blocks of solid matter, which are just not rendered - so those should block line of sight in every case. I cannot think of any case where it would be useful to have them behave otherwise.
Btw, there is another annoying problem with nodraw brushes which the combi lightclip/weaponclip/actorclip does not show:
Faces, which touch nodraw faces and are the same size or smaller, seem to get a nodraw flag in-game and are not rendered. This should also be fixed.