I have an external 750gb hdd that was formated by windows 7 to NTSF.I can edit, copy, paste & rename any file on the external hdd with windows. I can access the hard drive on my macbook but it won't allow me to copy, paste, delete or rename any file what so ever. Most of the files I try to edit are under 2gb. Is there a format that will allow me to copy, paste, delete or rename on both windows & osx?