When I try to delete files (that mysteriously appeared) on my flash drive, a message pops up saying "The file name specified is not valid or too long. Specify a different file name." The funny thing is, it has a funny name (which I can't change), there's more than one file (and all have different names), and it says that the file was modified on 8/11/2049... and that's not the only date, some of them have different dates. The file is not "read only". What to do?