Well the corruption is gone, just by it self with no flash at all. Probably after the card warmed up ( it wasn't used for couple days ).
Just in case I've performed suggested atiflash -p 0 -newbios orig.rom
to be sure that nothing left after 1950PRO.
Btw guys, anyone have idea now how to change the model of my card so it is detected as 1950 series ?