Back to My Mac is one of those 'wow' features of Leopard. It lets you connect, securely, to a remote Mac (running Leopard) and access files and control it from any other internet-connected Mac (which also has to be running Leopard). At least, that's what it is supposed to do. Many people, including scores of TUAW readers, are finding that Back to My Mac is fickle at best. It seems flummoxed by most router setups, and some people without complicated home networks are finding Back to My Mac performance spotty at best.
TidBits reports that Apple is aware of the problem (we should hope so!) and is working on it. Apple even responded to someone who reported a problem to assure them that a fix is in the works and should be available in the coming weeks.
As Glenn Fleishman points out, Apple usually doesn't admit to this kind of thing. Is this the dawn of a new, open era in Apple's dealings with customers? I doubt it, but I sure hope so. Either way, Back To My Mac users, or people who would like to use Back To My Mac, should expect a more pleasant experience in a few weeks.