Excel /flash drive problem

I seem to have a reoccurring problem w/ storing things on my flash drive. I rely heavily on it for personal documents because we?re not supposed to save personal data here @ work & I know (have actually witnessed) that my supervisor checks for such things when he is bored & deletes what he finds without a word to the person that did it. We have our manager?s permission to do our own thing if all our work is done ? as long as we drop it when something comes up.

It?s a San disk drive & I was running synch software that backed up my data on a PC @ home when I plug it in. The synch software stopped working a little over am month ago & I?ve had enough going on (family) that I hadn?t had much time to sit down & spend an afternoon on it (after about an hour I always seem have to go take care of someone or something). I?ve just been manually backing up my data.

I was working on an important spread sheet Thursday morning. I closed out of the drive properly (I always do). I did save something to it @ the public library ? I didn?t open anything though. The library pc is locked down so tight that you can?t safely remove the hardware (I can click till the cows come home but there?s no response) ? I have to shutdown the PC to get the drive to turn off ? could that be it? When I tried to access the drive this morning to work on my spreadsheet in Excel I got a flickering white screen & then ?unable to read file?. I backed up a copy of this spread sheet a week ago but I receive the same error on that copy. I thought it was the home PC but, I?m here @ work & it does the exact same thing. I don?t know if it?s something to do w/ a PC I?m using or what. Has anyone ever seen this? The open & repair does no good on this spreadsheet ? it did repair some other things this morning that were messed up on the drive. Any ideas?