I have a time capsule, and there is a common problem most people tend to have. All of a sudden, after a few months of the TC working great, I suddenly got a message saying, "The backup disk image failed to be mounted," or something like that. I was mystified and searched all over the internet and forums looking for an answer. It turned out that many people shared this issue. I learned a couple of weeks ago, a way to continue with the backups. It's simple. All I did was open a new finder window, click on my TC under devices, and I have another external drive connected to the TC, so I selected the "Time Capsule Disk" folder, just entered it, and with time machine in my menu bar, I noticed that it immediatley started backing up, it even finished my scheduled backups, until the next day, when I RESTARTED my computer. This seems to work for me most of the time. Try it out and see what happens. It really helps if you have Time Machine in your menubar so you can watch the status. Let me know if it works.