I am not sure where the problem is, but I think it something about finder. I want to copy some files from hard disk to my new usb flash stick. Although the 'get info' window of usb stick displays me bigger free size than the summary size of the files of hard disk that I want to be copied, when I click to paste them to usb stick, it displays me the error that there is not enough space in usb stick. What is the problem? Why such a big free space cannot accept the copied files with smaller total size? Example: why 25 gb of files of hard disk, could not be copied to a 32gb usb stick? I also made 'repair permissions' to hard disk and usb stick, with disk utility, but nothing changed. This is the first time I face such a problem and I really cannot understand it. Any thoughts on this problem?