I've got a MacBook Air 13" 2011 with a 128GB SSD. My problem is pretty simple: Lion tells me, that 98 GB of my disk space are used, which can't be true, because i don't have that many large files! In an attempt to investigate i used OmniDisk Sweeper to find out where my disk space has gone. To my surprise OmniDisk Sweeper tells me, that all the files on my hard disk only add up to 53 GB! That sounds far more reasonable but begs the question: what did Lion do with the other 50 GB and how can i get them back?