Hi Arc,
1) Try clearing the cache and see if that helps.
2) Otherwise, couple of workarounds you can try.
Instead of
RightClick "Save Image As..."
do
RightClick "View Image Info", then "Save As".
Though this involves 2 extra clicks.
Another one.
Load the picture. Then hold the SHIFT button, and Refresh/Reload the page. Then try "Save Image As ..."