Unable to overwrite PSD file. File Blocked

Can't overwrite PSD file, file blocked or haven't the authorizations required or file opened in another program. Since some months i start to get this problem and from today, PSD also DELETE the PSD file. if i move to another opened file and then try again, PHOTOSHOP let me save it. Why happen that? that is very annoying problem. How i can solve it? Thx