I first noticed that when a USB Flash drive (32gb) was empty but Get info showed it had 28gb used. And I couldn't add any files. I reformatted the drive and the problem cleared. Then minutes later my Time Machine allocated drive (Samsung 1TB Hard Drive) stated the back couldn't complete back up because I have no space. Looked on the Get Info and had few hundred MB left. When I know all that is on this drive adds to about 200GB! I really dont want to reformat this drive too. Any Ideas why this is happening and how can I stop it? I really dont want my internal HDD to do the same! PLEASE HELP!