Hmm did you try starting a new game with Raw? Because I think your current save right now is already not compatible... If not, try to run your game, then change the compression to Raw, then save as something new so that it'll produce the 512kb Raw save file and try to pokesavd those new file ...
Sry if i'm not helping so much, because my friend told me that his changing to Raw works well, but i don't quite know the detail ...