My son’s account on my computer is running Simple Finder with parental controls — he can only launch four apps currently (iPhoto, Photo Booth, SPORE Creature Creator, and Tux Paint, if you must know).
Recently, two of the apps’ icons in Simple Finder became blank generic document icons, and the apps refused to launch (they would bounce for a moment in the Dock before disappearing). So I dug around to figure out how to fix things.
Long story short: The Simple Finder “My Applications” window is in
~/Library/Managed Items/My Applications. I entered full Finder mode, deleted the two broken files, and recreated them as Finder aliases (by Command-Option-dragging the apps from
/Applications). Everything is as good as new.