download a copy and open it from your desktop and see if the problem continues. If it's trying to autosave a stupidly large file every time you drag something around then that seems like a fairly obvious potential issue
This. Someone needs to learn how to compress pictures for the medium. Unless you’re printing these for brochures, they don’t need to be higher than 150ppi
It's a 525 meg, local-and-Sharepoint slide-deck, running over my usually 800Mbps or so fibre connection, which it's auto-saving via.