Thanks negke, I feel a little better now. Fern said something about hulls, I must admit I don't know what are those, but checking the Quark log I assume that my map is split somehow in 2 hulls
------ GrowRegions ------
Processing hull 1...
----+----+
----+----+
Processing hull 2...
----+----+
----+----+
Looking at the map I see that it seems to be split in 16 zones, check the screenshot here:
http://www.abload.de/img/mapogyqh.png
So I thought to move all the map to the left to have the map in only 8 zones. If I cut a little from a long tunnel I could get it much better, only to one "zone".
Anyway, the first step was to move it only to the left a little (selecting everything and pressing left arrow a lot of times, keeping everything to grid).
But the map didn't compiled at all after that, I get
SubdivideFace: Didn't split the polygon near (-1920 1536 488), tech14_1
I encountered that error in the past when making long thin polygons, I only needed to scale the texture to get rid of the error.
Now I see the error after I "move" the map in editor...
Anyway, back to the question: what is a "hull"?
I noticed one time in the past that if I use noclip and I continue to move forward I end up soon in the "back", like I woul be teleported somehow. Does that has anything to do with the "hull" concept?