iPhoto se plante au lancement ?

Chaque fois que j'ouvre iPhoto, j'obtiens cette erreur :

Comment résoudre ce problème ?

Journal des erreurs :

Process:         iPhoto [52263]
Path:            /Applications/iPhoto.app/Contents/MacOS/iPhoto
Identifier:      com.apple.iPhoto
Version:         9.4.2 (9.4.2)
Build Info:      iPhotoProject-710042000000000~2
Code Type:       X86 (Native)
Parent Process:  launchd [240]
User ID:         501

Date/Time:       2013-02-04 17:06:44.306 +0000
OS Version:      Mac OS X 10.8.2 (12C3006)
Report Version:  10

Interval Since Last Report:          2832171 sec
Crashes Since Last Report:           829
Per-App Crashes Since Last Report:   7

Crashed Thread:  0

Exception Type:  EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000

Application Specific Information:
dyld: launch, loading dependent libraries

Dyld Error Message:
  Library not loaded: /System/Library/Frameworks/Python.framework/Versions/2.6/Python
  Referenced from: /Applications/iPhoto.app/Contents/MacOS/iPhoto
  Reason: image not found