Problem: I have multiple AppleTV’s running XBMC on them all reading from the same central server. The issue was that the thumbnails might be on one and not the other, also watching TV series its hard to keep track of which episode I am on since I watch from multiple locations.
Solution: Doing some reading you can actually make all of the XBMC instances store data to a central server running MySQL. Why would you want to do that? Well there are a few reasons, besides having everything in sync across the board it also gives you the ability to resume playback from where you left off in another room.