The problem with FAT32 is the largest file size is 4 gig. There are some software solutions that might help. One was NTFS-3G http://mac.softpedia.com/get/System-Utilities/NTFS-3G.shtml if the link still works. It switched to pay and most of the free links were disabled. Check post 6 in this thread http://community.wdc.com/t5/WD-Portable-Drives/unwritable-drive/td-p/435872 there a few other ideas.
Joe
