My Mac 10.5.8 has 149 gigs of memory. I currently have 7 gigs used. However, I am getting a system message that says I am out of memory. When I look at my hardrive, it confirms that 149 gigs are used. But when i look at each folder in the hardrive and add up the gigs, it only comes to 7 gigs. There are no other volumes in the Mac. The only thing that is mounted on the MAc is a 2.7 tb storage volume which should have nothing to do with the hard drive. Any advice on what is going on here?