I recently upgraded my hard drive to a MX100 SSD and also upgraded to 8GB ram. I followed instructions for doing a clean install from a USB bootable drive. Everything seems to have worked decently so far. I have not installed anything on the computer at this point in time. Problem discovered today was when using the Mac App store. When I select the Top Charts or Categories icons nothing appears. The Featured icon, Purchases icon, and Updates icon appear to be working. Thanks for any insight or suggestions you might have.