How To: Fix Desktop Switching
One of the bugs introduced in Leopard is pretty small, but significant to those of us who highly enjoy our Apple Experience. If Aperture is installed, users are no longer able to change which folder pictures are pulled out of for Desktop Switching. Adding a new folder will show a second, inaccessible “Aperture” folder.
Various troubleshooting steps included removing Aperture, and removing ~/Library/Preferences/com.apple.desktop.plist which is the file that controls the desktop settings. Neither of these worked though.
The fix is pretty simple and amazing really. Open iPhoto. Create a new, blank library. Close iPhoto. Go into Desktop Settings and feel free to add as many folders and you wish. In fact it may already be there if you had dual Aperture folders before.
After that, simply sit back and enjoy your auto-rotating desktop picture again.