Hmm, I forget what I did, but at school people would grab any floppy in sight and save their paper on it. Then strangely enough it wouldn't work. Sometimes I could recover stuff from it, but I never knew the rhyme or reason. Basically, if I remember right, try viewing it in DOS or your command prompt. There should be some sort of debug program in your computer or something like that that will try to fix the error. Or even in windows, check disk for errors sometimes works. If you check disk for errors and it saves the damaged data somewhere, you can sometimes recover that data (it'll be unformatted or something, but better than nothing).
Good luck.