.psd file trouble end-of-file error msg

I have a .psd file that I have saved.. Its like one of my greatest pieces of art/pixel graphics to date. I only saved one copy.. I really need to get this fixed.. I can see a preview of the art because with a .psd file the icon is like a thumbnail of the bigger image.. when I try open it I receive the following error..

Could not open v4.psd
because an unexpected end-of-file has occured.

I know its the file because I have tried it on multiple computers and multiple versions of photoshop.

Any ideas how I can fix the file..?