After a fresh boot I ran the Software Update and updated from iTunes 10.5.1 to 10.5.2 and Logic Pro from 9.1.5 to 9.1.6. After that I can't boot, I just get stuck on the Apple screen with the picture of circle crossed out. I don't remember having this problem in the past on Snow Leopard. Fortunately I have another partition I can boot to and run Disk Utility "repair" on it, which usually fixes these problems. Have any other Lion users out there run into this same problem?