1) What is the extension on the files? We search for all common image extensions but may be missing one.
2) Could you give us some idea what your photo folder heirarchy looks like? The photo quick access mode does some compression of the file heirarchy (to give a better experience with things like album art) and there may be an issue there.
I am facing the same problem. Let me know what the solution is. Photo option keeps searching for photos for several minutes and then the app ends. I can see those photos if I go to them using All Files option. I have more than 200 folders under My Pictures.