Some users have reported an issue in which iPhoto ’11 gets stuck on the library upgrade process that occurs directly after installing the program (as part of the iLife suite). Users experiencing this problem may receive a gray screen and a spinning progress indicator indefinitely.
Select library. Hold down the option key while you launch iPhoto ’11, then select your current iPhoto library, located in the Pictures > iPhoto folder.
Rebuild Library. Hold the command and option (or alt) keys while launching iPhoto to rebuild the database. Failing this, download and install iPhoto Library Manager and use its rebuild function.
Uninstall DivX. Some instances of this issue may be caused by the presence of the DivX codec. Look in /Library/QuickTime or ~/Library/QuickTime and remove the DivX codec then restart.
Delete keepsakes. Launch iPhoto ’09 and delete any keepsakes then retry launching iPhoto ’11 and performing the upgrade process.
Delete files from iPhoto package. Find the iPhoto application in the Applications folder (click Spotlight [magnifying glass icon] and type Applications) then right click or control-click the iPhoto application icon and select “Show Package Contents.” Delete the following files:
then restart your Mac and reattempt launching iPhoto ’11.