How bad does the floppy seem? Does it just give read errors?
This may sound a bit odd but this is something I found that used to work on my A500. I loaded DiskSalv from an external drive put any old disk in DF0: and got DiskSalv to salvage the disk. I think because DiskSalv directly controls the head (or something, I'm guessing) it moves it to the correct position. Or something like that, anyway it worked for me on a couple of occasions. Of course this is completely useless if you haven't got an external drive or the condition of the drive is serious.
