I had my MBP in for a repair (new logic board), but my hard drive was left completely intact. When I got home and hooked my computer to my external hardrive for a Time Machine Backup, Time Machine would try to create a new backup folder within the Backups.backupdb folder, rather than adding to the existing computer back up folder. It would then give me an error indicating inadequate space on the hard drive, which is of course because there are existing backups using the space and it was trying to start fresh. When I click on Time Machine in the dock, I can only see today's files, and I cannot access any previous backup dates. My system software is all up to date. I called Apple Care, but they seemed stumped, and kept me on hold way too long, before I decided to see if anyone here knew. Thanks!