My iPhoto library and folders display no pictures, simply grey boxes instead. Though there are JPEG's associated with every grey box. I can double click onto the grey box and the picture will display. Does anyone know how to get pictures displayed in place of the grey boxes?
Back Up and try rebuild the library: hold down the command and option (or alt) keys while launching iPhoto. Use the resulting dialogue to rebuild. Include the options to rebuild the thumbnails. This can take thre of four goes to work.