I bought a MacBook Air with the intention of being able to access some of my files from home on my iMac, connected to the internet with a Time Capsule. I logged in both computers with iCloud, and when I'm on the same network, I can use screen sharing and access each computer's shared folders as a guest or logging in with the user name, but when I try to connect with iCloud the dialogue box just shakes at me. If I'm on a different network, my iMac doesn't show up. Apple Support has been no help so far. Any ideas?