Free space disappeared in Mountain Lion

[frydrych]

I had 64 gb free on my Macbook air with mountain lion. Suddenly I lost 10gb for no reason and disc utility reports only 20gb free. So I have read some others posts that it might be a difference between finder and disc utility and that I should rely on finders free space.

So I tried to install something 23gb in size, with no luck since the disc is full. I ran disc utility and found some errors in reporting free space. Repaired but still the same and now there are no errors on the disc.

Ran Onyx and cleared everything I could think of, got back about 2gb.

Ran Omnidisksweeper and what I can see is that I have 48gb of used space. From my 128 gb disk it seems strange that I only have 57 gb free.

Disc utility reports me having 100gb used space.

Now when I think of it I had a friend who started installing World of warcraft yesterday to see how it ran on a macbook air but I quit the installer half way and deleted any trace that I found. Don't see anything taking up space that I can relate to WoW anyway.

Also reset pram and smc, no change...

Can't think of anything else.

Any of you guys have a suggestion?

Thanks

Fred