Thanks! As I mentioned above, this bug only starts to affect my game after a while. Restarting Sacred 2, creating a new character, or simply reloading the savepoint seem to temporanely fix it.
Specs are Win 10 64 bit, nvdia geforce gtx 980, intel core i5 7400 3.00 Ghz, 8 Gb ram. Audio and video driversare updated, along with the system. I honestly do not know how to fix it, but I do suspect it has something to do with the patch. The only thing I've changed is the command entry0 = {"et_mult_weapondamage", 1000, 0, 0, 9 } in spells.txt, but that's because it is recommended in the download page of the patch, in order to prevent a known problem. Hope someone can help me (I'm not at home right now due to work), because playing with against packs of enemies who hit me 10+meters away from my character is quite annoying.