I have a demo site at http://infodontics.co/simple. I had this set up exactly how I wanted it to look. I then noticed the other day it was not looking right. I realized that changes my users were making to their site via a custom theme were changing my demo site as well. This is frustrating as it has messed up my site's design (and this is the template for new sites). When I change them back in the demo site, it did not change on my users' sites.
So, why would they affect my theme, but me changing it back does not affect their site? I first thought it may be something having to do with sharing certain files...but why they would it not change for them when I changed it back?