Since last three days, I am trying to upgrade Xcode from 4.1 to 4.2. I am running Lion 10.7.2 an Mac app store shows an upgrade of Xcode of 1.8 GB Everytime it gets downloaded, then says installing and when done, it starts Re- downloading it again. Extremely frustrating. I can see Install Xcode.app In my applications folder and that lies there unchanged... What I understand for some reason the downloaded file from Mac app store Is unable to upgrade the existing 4.1 installer. Any ideas, workarounds?