Google recently changed their SSL search. Image search is now available over SSL. When you click on an image, Google redirects back to an HTTP url where they basically act as a proxy to the remote site.

Because this redirect URL is to host "www.google.com", HTTPS Finder flags it as 'known good' and tries to rewrite as HTTPS. Instead of forwarding back to HTTP again (where HTTPS Finder would detect the redirect and add it to the session whitelist), Google redirects back to www.google.com.

I'm currently looking into ways to fix this. The behavior seems rare, but may be present on other sites who proxy the way the Google Image Search does.

How to fix this on current versions: --Add "www.google.com" to the whitelist (Tools > HTTPS Finder > Preferences)

If you're using HTTPS Everywhere, just make sure the Google rule is enabled. HTTPS detection fails for the proxied image URLs, and so HTTPS Finder will whitelist them automatically.

Clarification to the above: There should be no need to whitelist manually if the HTTPS-Everywhere Google rule is enabled. In that case, you should experience this bug at all.

Fixed in version 0.67. Waiting on Dutch translation, then I will package as 0.68 and submit to Mozilla for review.

https://code.google.com/p/https-finder/downloads/detail?name=httpsfinder067RC.xpi

Fixed and released in 0.68. Closing issue.