So we have a Time Capsule setup. Old Macbook Air connected to it. Bought new Air. Originally they had the same name in Sharing "Vanessa's Macbook Air". Old Air works. As soon as new Air turned on, old Air gets kicked from the network, and is told none of the favorite networks are available, and can't rejoin the Time Capsule's network. As soon as new Air goes to sleep, BAM old Air is on the network. So I changed the names in Sharing tab of system preferences to "Vanessa's MBA 13" and "Vanessa's MBA 11" respectively. I also used DHCP to reserve each a different IP by MAC address. So one is 192.168.1.3 and the other is 192.168.1.4. So now it should work right? Nope. If the new macbook joins the network the old one is immediately kicked off. It doesn't happen the other way around. Also, the Time Capsule backup for the Old Air is corrupted, and Time Machine said it had to create a new backup and just toast the old one. What the HECK is going on?!! I'm completely stumped!