I was wondering if someone could help me diagnose a consistent problem I'm having in my maps where when the FPS player turns around quickly some objects and csg brushes have disappeared, revealing the skybox beyond, and then pops back into existence. I can't understand why, because my scenes can't be considered complex at all (The counter says approx. 1500 polys and around 4700 shadow polys with 4 lights in one map I've just started.), and the gameplay is otherwise super smooth. But it leaves me a little bit apprehensive about continuing because it feels like I'm doing something fundamentally wrong.
It's the east walls (if you look at the map from the above view in the editor.)
Using Leawerks 4.1 on Ubuntu 14.04 with a HD6670 graphics card.
start.map.zip