I'm now doing most of my stuff on the mac & noticed all my images saved on my PC to external drives are read only on the iMac. So I bought a western Digital, My Passport for Mac. its doing backups but I want to move files of images to it as the macs drive is filling fast. I either can't open images it did let my paste or gives error code 50 when I try to copy from hard drive or save from photoshop to it.Any ideas please.