We’ve been getting an unusually large amount of user submissions about issues when upgrading from iPhoto ’09 to iPhoto ’11. Specifically, some people are losing some or all of their photo libraries when upgrading. Also, iPhoto ’11 drops support for older AppleTVs as well as photo calendars.
So, don’t let Apple’s consistent delivery of fine software lull you to sleep. Back up your photos and videos before doing the $49 iLife ’11 update.
One solution if you are having issues:
Repair permissions in disk util.
Try deleting the Delete iPhoto Pref File
iPhoto preference file, com.apple.iPhoto.plist, that resides in your User/Library/Preferences folder.
NOTE: If you’re moved your library from its default location in your Home/Pictures folder you will have to point iPhoto to its new location when you next open iPhoto by holding the the Option key. You’ll also have to reset the iPhoto’s various preferences.