Primortal: I've tried all the possible fixes... and it still doesn't work... or can't get some to work, like a suggestion to revert to 'directx8'... don't know how to do it, since i don't think i HAD directx8
Well I dont have the problem that you have but if you want to launch the directx8 version I can tell you how to do it.
If you are using gog galaxy go to the game page then More--> and you will have to choose to launch the directx8 version.
If you are not using galaxy you can go to the game files where you installed the game and you should find the executable file. I can't remember the file name because I don't have the game installed but it should be something that has a dx8 for it's name.
Also the directx8 version at least for me fixed the long loading times when entering a battle , going to a different place or opening the menu.
Hopefully this helps you, sorry for my bad english.