Not nessasaraly. I have my cache set very small... So everytime, I'm sure I get the new version of a page. Your cache size will varry. If you view alot of pages inbetween comming to terraforums, other pages will "take" that cache space. And the TF cached images are lost. And then will be redownloaded once you revisit here. So to say "those images only need to be downloaded once" is simply not true. Although, if you don't browse much on the internet, or mainly only view this site. Then you are probably correct.