Do you want to start from the time you saved, or from the time of last change.

I have contacted Customer Service about a problem that pops up almost every time I sign on and want to update my site. It keeps saying: After you saved, we detected a change to your website. Do you want to start from the time you saved, or from the time of last change. Why am I getting these. I know my account hasn't been hacked. I save every page I change. I publish (and wait for the publish bar to complete) every page, plus I publish all pages before signing off.