Why do Final 판타지 IV The After Years corrupt all saves?

Whenever I play my Final 판타지 IV The Complete Collection to my PSP and I play Final 판타지 IV and Final 판타지 IV ~Interlude~ it works fine.But whenever I play Final 판타지 IV The After Years and advance a little at Ceodore's Tale all my save data corrupt.Do 당신 know if it has a problem 또는 something because it's really annoying.