Yes, the edited photos are there, the thumbnails are there, but some pictures are black and 0 kb unless you revert to original photo. It is frustrating because it does not happen on all edited photos, only some. As I said, I have had the problem on Sony, Nikon, and Fuji cameras and I am running 10.7.5. It also seems to happen when I have big libraries like after a trip where I have several hundred photos. I can't confirm that, but I don't seem to suffer the same problem if I edit one or two photos in a Library of less than 100.
Another problem I am having with iphoto is that when I plug my iPhone in and the pictures are being imported, the thumnails just appear gray. The photos are there and they do upload, but you have to import all since you can't see the thumnails.
I am just managing with my iPhoto at this point until I have time to do my homework on other software like Picasa or Lightroom. It is dissapointing thought since all of my devices are Apple products.