are you using a dsi? if so try the card, and your back-up roms on a ndsl or ndsp. make sure your loaders are updated. try formatting the msd. no one can really help you with this until you try to debug it fully. try everything you can think of and test for at least a week. if your saves continue to get corrupted after you have formatted, tried other loaders, tried the official, etc... then parhaps its an akaio issue (which i seriously doubt). at this point, if i had to guess, i would say its a msd contact issue with the cheaply made ak2i.
-another world