Time machine (1TB external drive) keeps saying its almost full and only has 40GB left. My Mac HD is also 1TB. To help time machine have room i deleted a bunch of stuff off my Mac HD after transfering it to a third (unrelated) backup drive. Now my Mac HD has 140GB of free space. I figured this surely would be enough to calm down time machine. However Time Machine is still upset and thinks it doesnt have enough room. I assume time machine is keeping a backup of the stuff I moved to the external drive, plus copies of copies of copies of god knows what. How do I make time machine happy again??