Vet inte om detta hjälper, jag läste det på Apple discussions, kopierade
ut det och sparade som textfil...
Make sure the iPhoto is not running, and from the Finder locate and remove the Thumb32.data, Thumb64.data, and ThumbJPG.data files out of your iPhoto Library folder. There is a chance that these files have been corrupted and need to be rebuilt. When you try launching iPhoto, these files will automatically get regenerated. Please let us know if this fixes the problem.