I am having 2 problems since I switched from a 2007 iMac to a new Mac Pro. First, I installed an SSD as a boot drive and reinstalled Lion then used Migration assistant to copy my files from my old mac to my new mac pro. I also have a 1TB drive in bay 2 for files and media. Apps and OS are on SSD. Now when I click on an app the I originally downloaded from the App store I get a pop up message saying, "App was purchased using App Store on another computer. To install App on this computer, sign in using the Apple ID and password used to purchase it." I enter the info and nothing happens. Second, when I open the App store and try to update an App, I get this message, "There was an error in the App Store. Please try again later. (100)" I have tried everything I could think of to get this corrected short of reinstalling the OS and starting from scratch. Deleted the appstore cache file, restarting, downloading a free app in iTunes, etc. Does anybody have any indication of what's going on or how I can fix it without having to start over? Thanks.