Recently I had a font issue after upgrading to Mountain Lion. Despite attempting various fixes, nothing solved the problem.
The only solution was the create a new Administrator Account. This solved the problem.
In order to access my files from my new administrator account, I set permissions in the old administrator account to share publically and so I have been able to move my photo, music and movie files across into my new administrator account's folders.
For example: I moved my iTunes libruary from my old administrator's account folder into the new administrator's account's music folder, same with my iPhoto library etc.
The question I now have is; if I delete the old administrator account, will those 'shared' folders also be deleted?
iMac, OS X Mountain Lion, 27 inch - 8GB memory - 1T HD