maya 2008 file corruption
 

I have made several copies of the same file at different stages, its got quite high res models in it. Now whenever I try and open any of them, it says there has been data loss. I.e. i think its corrupted. half the model is gone. It hasn't been crashing whilst ive been saving. Does anyone know how I might retrieve the files/ stop it from corrupting them in future? Its pretty awful. ive lost all my work ;(