Unable to open keynote presentation file - file corrupted?

Hi,

Today I tried opening my keynotes presentation file to make amendments to it and when I double clicked on it, the program loading bar only loaded up a third of the way and then hanged. I then tried to save it to a flash drive and use it on a different computer, but when I tried to copy it over to the flash drive it gave me this error:
"the finder cannot complete the operation because some data in "garment styles" could not be read or written error code - 36".
I have tried changing the file extension to a zip, then unzipping it and then renaming it but that did not work.(It wouldn't let me unzip it). I have also looked at the index file name to see if that was the problem, but that is as it should be.
I have also tried uploading it to a website and emailing it and it will not let me.
Is there anyway I can recover this file as I have been working on it for over a month and it is due next week, or will I need to start again?

Thanks