I have been having similar problems with floppies for a couple of years now. Disks that read fine an hour or a few minutes before would report as not being formatted. Sometimes they could be reformatted and sometimes not. I have lost the data on floppies that I made 1 minute before. Each time I had trouble I tried different drives/cables/systems etc. and the problem persisted. To this day I have never solved the puzzle. I bought brand new disks and half of them reported as not being formatted and some simply didn't work anymore a few days after putting data on them. Even now I cam pull some floppies out of storage and I can guarrantee that at least half will show this problem.......like I said, I am still confused too.