IPhoto '09 seems to be incompatible with Mountain Lion

Question

Hi
I am a long-standing major fan of Apple computers. This is because they allow me to work easily with images. I am an art historian and museum curator. My professional life is entirely about images ... or rather about images attached to data.
For years I have been accumulating and categorising images using iPhoto. It has been the most wonderful tool. A clear, simple interface. The capacity to attach searchable free-text metadata. Wow, that simple feature makes this the most powerful application of any I have ever used.
The problems started for me when iPhoto '11 first came out. This removed the capacity to compare photos side by side in full screen mode, a brilliant, simple and obviously powerful feature. As a consequence I did not upgrade, but stuck with iPhoto '09 (8.1.2).
Now I discover that there seems to be a bug which means iPhoto '09 is not compatible with Mountain Lion. Whenever you go into Preferences the computer seizes up and has to be hard-booted. An Apple genius was unable to fix this for me. I've reinstalled the entire operating system to try and fix the problem, but it remains. I gathered from a discussion thread that it was simply an incompatibility with Mountain Lion.
As a consequence I have purchased iPhoto '11 (9.4.1) and Aperture, which I was advised by the Apple Genius would be much better than iPhoto. I have converted my several iPhoto libraries. But I just cannot get anything resembling the clean functionality of iPhoto '09. Everywhere I am cluttered up with gadgetry which I cannot remove. It just is no longer possible to view photos with their basic metadata in a clear and simple way.
The only way I can see forward is to downgrade to Lion, reinstall iPhoto '09, and live the rest of my life without ever upgrading to Mountain Lion.
Forgive the long rant. I am sure people will be irritated and say I should not be using an application designed for holiday snaps for professional purposes. But that is not how I see it. iPhoto is part of the fundamental suite of utilities which makes an Apple computer what it is. That means it ought not to be designed with a single purpose in mind. We are creative people. We use our machines as it suits us to use them. Apple became what it is because it understood that.
If anyone can point me in the direction of a image organiser which allows me to store photos with associated searchable free-text metadata, add dates of my own choosing to the images and to do this in a way which integrates with other applications as well as iPhoto, I'd be so very grateful.
Otherwise I think it's going to have to be the downgrade.
Or could this even be the moment come to abandon Apple? I'm due for a new machine. For the first time in 25 years and six Apple computers I'm going to be considering the competition. Any helpful suggestions would be very gratefully received.
Thanks.

Answer 1

Yes, that's it! You're brilliant. Thank you so, so much.
Just in case anyone else reads this having had the same problem, the answer is (as Terence says) to delete anything which might cause the computer to try to link to a MobileMe account. My iPhoto libraries had old MobileMe photo galleries which I hadn't bothered about in years. It seems these caused the iPhoto Preference pane to attempt to access MobileMe whenever I opened it. This of course it could not do because the service is defunct and so the computer simply beachballed. In order to remove the MobileMe galleries I found I could only do it if I first disconnected my wireless network. All MobileMe references are gone now (I hope) and everything seems to be working well.
Hugely grateful.
(Sorry clicked the wrong message for 'Answered my question')