I'm using iPhoto '09 v8.1.2 under Mac Lion OS v10.7.5 on a Mac Pro 1,1. I recently upgraded to a new hard drive, and nearly everything transferred over just fine, but iPhoto is not working correctly. I get no thumbnails in the grid view, which pretty much breaks the app for me. I have tried Apple's recommended fix of launching iPhoto with Cmd-Opt held down, which brings up the rebuild thumbnails dialog box: I've done this a few times, but it does not fix the problem. I can't navigate my iPhoto library without the tumbnails, and it's already messing things up for me. I make heavy use of Keywords and Names (which is why I haven't upgraded to a newer iPhoto) but they're useless if I can't see previews of the images when I search or try to manage my library. Does anyone have any ideas to get preview thumbnails working again? Thanks!