Area Portals Going Insane!

[Tynan]

Hey guys, I'm optimizing my map with area portals.
Some of them work perfectly.

Others do this:

It just renders the skybox. I can walk right through it fine.

They're all set to initial state=open. What should I do? I can't see any difference between the buggy portals and the good ones.

 

[The Dark Elf]

make sure ALL of them are open, and that no errors come up when compiling. Also the placement might have something to do with it.

Also make sure they're as thin as possible.