Ben Van Houtte wrote:
There is another long thread of people reporting the same problem: http://discussions.apple.com/thread.jspa?threadID=2132636&tstart=30. Apparently after upgrading to SL Time Machine tends to start a new series of backups but the old ones are still accessible - even though this is more complicated than it should be.
Deleted backup /Volumes/Home Edition/Backups.backupdb/Kona/2009-11-25-135735: 27.79 GB now available
Removed all 1 expired backups, more space is needed - deleting oldest backups to make room
Deleted backup /Volumes/Home Edition/Backups.backupdb/Kona/2009-11-26-020229: 27.83 GB now available
Deleted backup /Volumes/Home Edition/Backups.backupdb/Kona/2009-11-27-145456: 28.02 GB now available
Deleted backup /Volumes/Home Edition/Backups.backupdb/Kona/2009-11-28-032652: 28.09 GB now available