Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
iPhoto 9.2 Released and now supports iCloud and Photo Stream Support –
More and more software.Apple has just released a iPhoto update to go nicely along with your IOS5 and Lion 10.7.2 software update.The update allows your iPhoto to work with iCloud and the Photo Stream feature. The photo stream allows you to view photos taken on your iOS 5 devices . The 376MB download requires OS X Lion.
– Left and right swipe gestures can now be used to navigate between photos in Magnify (1-up) view
– Previously imported photos are now displayed in a separate section of the Import window
– Book/calendar themes and card categories can now be selected using a pop-up menu in the carousel view
– Resolves an issue that could cause some pages of books to print incorrectly
– Rebuilding a library now correctly preserves saved slideshows and books