Mountain Lion has moderately broken the hack I originally used to retrieve the background image names in this posted question: How do I reliably get the file name of the current background picture?
The com.apple.desktop.plist file is not updated immediately when the background image changes - it appears to be delayed by around 30 seconds, which makes a once-a-minute randomly changing background image name wrong half the time.
Is there a way to force an update of com.apple.desktop.plist?
