I have an iMac that tells me it's hard drive space is completely full (it fluctuates between 450MB to 160MB free?). It's a late 2011 base model w/ a 500GB HD. I have no idea what is causing this, as I have heard Lion does automatic backup w/ Time Machine, but I have Time Machine disabled on this Mac. What could be causing this as I've only used about 1/6 of the space on the drive and it's relatively new... help would be greatly appreciated and thank you for answer in advance. NOTE- I mistyped the title, it's supposed to be 2011, sorry.