(GZdoom) Transparency issues in hexen levels with fog.

[Ashurion Neonix]

Whenever I play hexen levels with fog through GZdoom I get this wierd effect where all transparent wall textures (middle) appear black where there should be transparency. Sort of like when you put them on a single sided linedef. This black effect dissapears when I get close to the affected wall. I've tried altering various texture, renderer, and fog settings without any success.

My ini file: (yes the username is a joke)

gzdoom-N00bularXD.zip