I have carefully implemented the disc image option described in the Apple support document HT1198 on sharing an iPhoto library between multiple users but it isn't working. User1 copied 20GB of photos from a USB backup disc into the newly created library on a sparseimage located in users/shared and can now access it without difficulty. User2, mounting the sparseimage and starting iPhoto with Option and choosing the disk image iPhotolibrary is consistently barred by a Caution - volume locked message. 1) I have ensured the 'ignore permissions on this disc' is ticked 2) I removed the default iPhoto libraries from both profiles 3) I have given User2 read and write permissions to the files on the disk image: she appears on the 'get info' table with read and write permissions but when she logs in it also tells her above the table that she has read only access 4) I have allowed the system to repair permissions (several times). What to do? Can the permissions be corrected via terminal?