XF 1.4 Problem with SSL

in the URL bar for my forum the "https://" stays green for a split second when loading the site, then it pops up with a lock and when clicked says their is unsecure content on the page/site.

I've gone through and changed all the usual stuff like board title, home link, etc, etc, every link that would pull something from http:// is changed to https:// I also have a .htaccess edit forcing the site into SSL/https and on the page source I can't find any other "http://" links yet its still saying the page is unsecure?

Any help at all would be appreciated, its a RapidSSL cert.

board link: https://forbiddense.com/index.php
@Brogan thanks, you've helped me getting it fixed on the homepage of the site, now however it seems that in threads, my problem is my members link to images in their posts to sites such as imgur, or gyazo, which results in the HTTPS/HTTP content conflict again;

is there anyway to fix this?