Ok problem solved there was a folder inside the BG2 directory called "portraits" which holded all the new portraits of Sola, Valen and Suna Seni so it had to be replaced as well.
I've installed sola mod from the beggining like all other mods, and I've played through all of Usta'Natha sequence and since I hated his default portrait so I changed it to another from the weidu site, but for some reason it won't change the small one only the big one in the charachter info page, I've tried re-installing but it's still the same... what do you think?