how to turn iPhoto back to older version?

I did that Software Update for my Mac ...it had its repercussions.
So every time when I am trying to open iPhoto 5.0.4 app
I get the message

" You can't open your current photo library using this version of iPhoto.

You have made changes to your photo library using a newer version of iPhoto. Please quit and use the latest version of iPhoto. "

(with only choice of action is pressing Quit button).

So I cannot access iPhoto at all now.

I don't have any newer version of iPhoto lying around this laptop.

Had anyone same problem? Any idea how to get old iPhoto back?

can you just simply move all the image files out of the pictures/iphoto library folder to another location, then re-import them?

i refuse to use iphoto, but i'm guessing that may work...

What is the reason you are trying to use 5.0.4 and not a newer version? Maybe someone can resolve the problem so that you will not have to go through the trouble of down grading. Because depending on how many picture/images you have in you database, it may take a good period of time to get them out of all the directories/folders. It maybe easier and quicker to resolve your current problem with the newer application.