I can't figure out where 120 GB of Hard Drive Space has gone. I've scoured other similar threads, but none like this:
1 - 451 GB are listed as being used (in Finder/About My Mac/Whatsize/Activity Monitor/etc)
2 - outside programs, including WhatSize, list less. For example, Whatsize (which I paid for), only finds 331 GB of used space (but lists 451 GB as "used" in the upper left corner).
3 - commands like sudo du -hd1 only show me using 284 GB.
I'd like to find WHERE the 120 GB is being eaten before trying to figure out WHY. But I got into the root directory in finder anyway, and found nothing unusual.
More information - I'm using Snow Leopard, I was using Lion earlier but got tired of "Out of Memory" errors (when only 430 / 500 GB were shown, but all sources, as being used). I erased the hard drive in Disk Utility and did a clean install, last week. At that time, I was "using" 410 GB after reinstalling files- so 40 GB have gone missing just this week (I'm not doing much - No, it isn't because iTunes or iPhoto are making copies of things). I should say, overall, the system is screaming fast and working like lightning and I'm happier (compared to Lion).
And finally - the first thing that happened when I bought this laptop was that I had a logic board failure. Literally one day out of the box. So maybe this computer is a lemon. This is my first Mac too.