This seems to be a not uncommon problem but I still haven't found a solution. We have a ReadyNAS Duo set up for Time Machine support with AFP and CIFS enabled and opportunistic locking disabled but the ReadyNAS doesn't show up when I try to select a backup disk in Time Machine. We have two early MacBooks both with Snow Leopard and neither of them can be made to work. If I do a direct connection to the ReadyNAS via Ethernet cable the ReadyNAS share shows up so the problem would seem to be a network one but I can't for the life of me figure out what it is. Has anyone any suggestions?