Skotty wrote:
I guess the easiest would be to give the VMF to some experienced person, like lpfreaky, Chicken or me, and we will find out the problem.

The .vmf was already posted some posts ago

josepezdj wrote:
(...)
- Increase the lightmap scale for the texture in the angled wall and the adjacent wall (up to for example 64)
(...)

Well, 64 didn't fix the problem, but... 120 did.
120 was just I value I came up with, more or less double 64. And it worked. cheers
Thanks everyone who tried to help me, specially @josepezdj for his devotion. ^^

Screenshot:

I'd recommend you to use a number power of 2 though, like 128 instead of 120

FelipeCaners wrote:
Yes, I had already set to 128. Just so you know, rotating the map affects that shadow, although it doesn't fix it.

Haha... crazy VRAD!