Tenebrae has problems running map e3m3 from the commercial Quake 1 episodes. According to http://www.inovagames.com/q2k4/news.html (in the 2004/07/31 news entry) there is an extra angles attribute in the .bsp file, which causes the world to be rotated oddly, in relation to the entities (items, monsters, players) in it.
I have created a patch based upon a fix inserted into the darkplaces fork of the quake engine. Basically, quake worlds aren't supposed to be rotated, and I made the engine zero out any rotation after loading the map.
Created attachment 48166 [details, diff]