Hi all, When I updated my MBP to Mavericks, it was very slow and buggy for me. So I decided to do a clean install. But whenever I get to the part where it says "Signing into the App Store", it gets stuck on the spinning rainbow wheel. Is it because Mavericks is not officially out yet? I do have a backup of 10.8 on my old hard drive, but how would I go about fixing this? Any help would be great.