Dan, I had that issue before. I finally just ended up deleting it and reposting it, but you lose any comments or votes. You can put this problem in the "Bugs and fixes" thread...Just search in the thread box for "bugs" and that discussion will come up.
it's that cache thing, clear the cache, refresh and it should be fine. because it erases the old picture, so it's not there. sometimes its better to get off the picture, erase the cache, then load it again.
Found the problem....After "change image" you need to go to the bottom and select "submit". I didn't select "submit previously. Then I used your suggestion to refresh and there was my changed image. Thank you all for your help,