Currently Being ModeratedDec 5, 2013 11:58 AM (in response to TaraLeeSav)
Have you checked, if the photos, that should be visible at the black spots are o.k.? Perhaps the connection to the original image files is broken. Try,if you can edit or export the photos in question.
If the photos cannot be edited or exported, try, if rebuilding the iPhoto library will fix this.
How to rebuild the library is described here by Old Toad: