I bought a MacBook Air this summer and it came with OS Lion Installed. I upgraded the machine to Mountain Lion and have had many problems. We did the same with our iMac and are having the same issues/problems. I decided to wipe out the OS and reinstall Lion since I don't recall having any problems with that OS. Since the MacBook Air doesn't come with OS discs, you have to do the Command-R on reboot. The problem I am having is when I did this it only gives me the option to reinstall Mountain Lion even though Lion came with the machine. I am assuming that when I upgraded to Mountain Lion it overwrote the Lion restore software with the Mountain Lion. Is there any way of going back to Lion or am I stuck with Mountain Lion? Thanks!