reasons for corrupt file

My nephew had the memory card in the ps2 and was ready to play Def jam fight for NY and it wouldn't load from the memory card (start of game)he said it said something about can't load maybe file is corrupt.

I've looked around(searched ) put can't really see what the various reasons are for something like this to happen. I know if you turn it off while it is saving that can cause it but are there other reasons.

Had no problems in the past saving and loading from the memory card when playing this game. hasn't happen on any other game and he copied over the corrupt file saving his progress in def jam. and it's loadings now from the start of the game.

thanks,


john merrick