Your buglife link is issuing login requests
Fixed.
Notes (added in edit):
Originally, just clicking on this page resulted two password prompts (with firefox). I changed the image to a link, because viewing an evcforum page should not require a "buglife.org.uk" password.
AdminModulous then kindly added a link to the page at buglife. The image is on that page. After viewing that page, you can then directly click on the link for the image (in case you didn't work out what it was). It should now work, because your browser will be getting the image from your browser cache instead of from the buglife site.
Edited by AdminNWR, : added notes