All about iPhoto
All depends on where you are at in terms of new or established Mac. Mine is fairly new and this all started when I went to change pictures on my monitors. I had not set up Time Machine, so I did not have a good image to revert to.
I put everything of worth onto an external hard drive, deleted iPhoto, then reinstalled Lion. That did the trick, and I immediately activated Time Machine.
Today I went to change a picture, it hung, and I just did Command/r on start-up and opted to restore from Time Machine, and used last image from when things worked well.
All good, albeit annoying. That System Preferences is that vulnerable ,,, or that iPhoto corruption can affect this very essential utility ,,, I think those need to decouple.