Free Space Discrepancy

[X5-452]

Poking around my new 13" i5 I noticed something.

Finder says I have 156.85 GB of space free
iStat nano says I have 141.76 GB free
System Information says I have 152.21 GB free

I have a 256 GB SSD. Anyone else reporting various free space??

On an additional note, which one should I believe? I'm inclined to say Disk Utility / System Information is right...

 

[Oli3000]

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_5 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8L1 Safari/6533.18.5)

Restart and they should all read the same - it is to do with garbage collection I believe!