Problems when swapping portraits

[KPT25]

Recently i was in a rush of changing some of my characters` portrait so they look better when i select them...it worked well with all of them,except for a few...after i changed the portrait for a new one(which i requested in the portrait section),although i actually replaced the sprite for the new file.pcx,the portrait doesn`t appear anymore(character is selectable though)
Does anyone has an idea of what could be the reason?I save the png file that the portrait originally had into pcx with the  Nero Photosnap pic viewer...did i do something wrong?thx in advance...

[A!]

something up with the pallettes

[KPT25]

Probably...but how could i fix it...any idea?Because i tried with the 2 portraits that were made for me(check my post at Portraits thread) and neither of them worked fine...so it should be the portrait that screws up when changing the format from PNG to PCX