I lost all of my pictures from my iPhoto after updating it to the newest version. How do I find them?
Have you pointed iPhoto to your old library (In iPhoto: File>Switch to Library)?
I also recall that it said: "The photo library needs to be upgraded to work with this version of iPhoto." when I updated. Did yours do this? I notice also that there is a quit option, did you just click through thinking it was junk?