Ken, I'm having trouble finding where that preference is set. I'll keep looking. I didn't change anything. I know for a fact that I have two tabs that do not do a fresh fetch on workspace load because I just refreshed them manually.
The Astronomy Picture of the Day (
http://antwrp.gsfc.nasa.gov/apod/astropix.html) and Earth Sciences Picture of the Day (
http://epod.usra.edu/) do not fetch new versions when the workspace loads. But those update again only once a day.
I think this page is also not updating and the plots are refreshed every few minutes, so you can see the change if you note the time:
http://www.spacew.com/index.php
(Also sent via feedback)