This is a followup to the problems I was having with Time Machine backups to Time Capsule. Time Machine would start preparing a backup and after about 10 would fail. After a few weeks of failed backups or backups taking hours I called Apple support. They had me try several things including reseting Time Capsule. One of the things that we tried was using the Disk Utility to mount the sparse bundle files as a OS X volume. That's when I got this error message.
After almost an hour on the phone with first level and second level support I decided on a drastic course of action. I used the AirPort Utility to erase the Time Capsule disk. Once that completed I configured Time Machine to point to the Time Capsule disk and Time Machine has successfully completed two weeks worth of backup.