Hi - I upgraded my mac to os x mountain lion a couple of days ago and yesterday , I found out that according to Finder I ‘lost’ a lot of hard disk space. I have a 160G hard drive and before the upgrade (Snow Leopard) I had only used 50G so I should have 110G after the upgrade. But after the upgrade, Finder shows I have used 130G and only have 30G left. I then went into disk utility and it also provided the same info. I ran verify disk and repair disk permission, to no avail. I then ran OMNI Disk Sweeper but after running it, it confirms that I only used 50G, so I should have 110G left but for some reason it is not showing…..on Finder and Disk Utility. My Trash is empty and I use external hard drives for back up and to store iTunes content so I don’t understand how I ‘lost’ so much hard drive space……how do I regain the space?? Please help!! BTW, I also goggled this and found a number of people seems to have the same problem…but none of the messages offered any solution to this……I am really stumped…..Help!!