Currently Being ModeratedAug 20, 2011 4:47 AM (in response to julienfromcugy)
Try trash the com.apple.iPhoto.plist file from the HD/Users/ Your Name / library / preferences folder.
(On 10.7: Hold the option (or alt) key while clicking on the Go menu in Finder to access the User Library)
(Remember you'll need to reset your User options afterwards. These include minor settings like the window colour and so on. Note: If you've moved your library you'll need to point iPhoto at it again.)
What's the plist file?
For new users: Every application on your Mac has an accompanying plist file. It records certain User choices. For instance, in your favourite Word Processor it remembers your choice of Default Font, on your Web Browser is remembers things like your choice of Home Page. It even recalls what windows you had open last if your app allows you to pick up from where you left off last. The iPhoto plist file remembers things like the location of the Library, your choice of background colour, whether you are running a Referenced or Managed Library, what preferences you have for autosplitting events and so on. Trashing the plist file forces the app to generate a new one on the next launch, and this restores things to the Factory Defaults. Hence, if you've changed any of these things you'll need to reset them. If you haven't, then no bother. Trashing the plist file is Mac troubleshooting 101.
Currently Being ModeratedAug 30, 2011 2:35 AM (in response to julienfromcugy)
To re-install iPhoto
1. Put the iPhoto.app in the trash (Drag it from your Applications Folder to the trash)
2a: On 10.5: Go to HD/Library/Receipts and remove any pkg file there with iPhoto in the name.
2b: On 10.6: Those receipts may be found as follows: In the Finder use the Go menu and select Go To Folder. In the resulting window type
2c: on 10.7 they're at
A Finder Window will open at that location and you can remove the iPhoto pkg files.
If you purchased an iLife Disk, then iPhoto is on it.
If iPhoto was installed on your Mac when you go it then it’s on the System Restore disks that came with your Mac. Insert the first one and opt to ‘Install Bundled Applications Only.
If you purchased it on the App Store you can find it in your Purchases List.