Hello to the forum, this is my first post here. I'm from Italy so I hope you'll forgive my bad english. Lately I'm having some serious issues with my mid-2010 iMac. Everything started when i freshly installed Mavericks (by freshly I mean an "erase&install"). Soon after that my mac started panicking randomly, so i checked disk with Disk Utility and the "incorrect node" error message appeared. DU was unable to repair disk. So i smelled something wrong and went straight to another fresh installation, from a usb drive, after repairing disk from there (it was successful, this time). No luck tough, a generic error stopped the installation and when i went back to DU (from mavericks installation - usb) the same error showed up ("incorrect node"). After that i scouted the web for possibile solutions, and i tried almost everything: - Resetting PRAM - Resetting NVRAM - Disk Warrior - Different OSs (including SL, L, ML). - Single User Mode, Safe Boot - Target disk mode (to repair permission/disk) - Swapping to another HD (that i knew it was a functioning one) No luck. I was desperate. Then I tried one last thing, found on a dark and scarcely populated forum. Removing a Ram bank ( I had 2, 2gb each). And -tadaaaa- Mavericks installed like a charm with a 2gb Ram card. BUT -and here's my current issue- now i can't mount more than 2gb, every time i try to put on my brand new 8gb single-bank Ram card, the system boots up, runs for a while, and as soon as I open more than two programs, screen goes black and reboot. If I just let it quiet without touching it, it stays up for hours. Same results with 2x 2gb original ram banks. I am quite desperate, as you may guess. Any hints on what's going on ?