suppress document save warning when no changes done

Is there any way to stop the save disk icon from turning on even if I switch documents?  It's really annoying and makes me wonder if I already saved or not and some documents are huge so it takes time to save them.

It must have something to do with how the document is monitored in terms of the 'dirtyiness' of it and some things are picked up and registered as a dirty doc when it really isn't.  Anyone dirty?