Time Machine fails
I set it for 1984 and I didn't go anywhere. Just kidding. It looks for the backup drive (which I know is connected as I can mount it and view contents). Then it says "TIme Machine could not complete the backup. The backup disk image [....] is already in use."
This happened a week ago and I completely erased the Time Capsule and reformatted. My Mac Book took well over a day to back up on 74 GB and my wife's Mac Mini (270 GB) took FOUR DAYS to backup again.
So after reformatting, it worked OK for about a week, but is not doing the same thing again.
Any ideas?
MacBook Pro, Mac OS X (10.7.5)