On Wednesday, July 30 2014 a Facebook cover photo for a Fan Page suddenly moved without any notice or editing of the page. The photo was "pushed down" so the cropping was in the improper position. Instead of showing police cars on the street, the cover photo showed the tree canopy above the police cars.
Using the repositioning command did not work. Even though in editing mode the directional cursor would allow re-positioning of the photo in a manner that appeared as though the positioning was fixed.
Re-uploading the photo did not correct the problem.
The only correction was to re-size and/or crop the photo in Photoshop, and upload the new version.
The bug was only occurring on one Facebook Page (http://www.Facebook.com/ArlingtonHeightsCrime)
The bug was not occurring on any other pages.