Time Machine tries to connect when I'm away from home
I have done two things in this case.

1) Connect a hard drive to change the destination - even if I don't connect that drive often, the local drive check seems faster than a network check. You can then re-establish the network backups to no ill effect when you return home. Having many Time Machine destinations is nice to have a second copy and works well for me.

2) Log into your Time Capsule and sign in again to MobileMe / iCloud and then delete that "find my mac" functionality. This seems to lessen the Time Machine "seeing" the remote drive but has an obvious downside of not being able to re-connect as well to your "home" AirPort / Time Capsule while on the road.

For advanced debugging, you could also run tm_diagnose and pore over the logs collected to see if any error conditions are present in the extremely undocumented and verbose logs that the diagnostic command collects. I would caution people without a UNIX or software background that "errors" in system logs are often not errors in the sense that something is broken - but more for the people who write and maintain the code to remember to clean some thing up or a minor "assumption" was not proven out in practice. There can be lots of false positives when looking at unix logs, but also a lot of learning how things work under the hood.