Find out what resources are not going over HTTPS
I've just had this problem in Chrome also. I checked in the Network tab but all resources were loaded over https.
Solution: close Chrome and re-open.
Chrome must cache its secure-content detection so that even when you fix the problems the insecure content message won't disappear.
Usually this occurs because you are loading Images, javascript include files or external CSS files without using https. You can use a program such as FireBug: http://getfirebug.com/
FireBug will tell you how your elements are loading and which aren't going through the ssl layer. If you don't have firefox, then I am pretty sure Chrome also has something similar to FireBug built in.
Here's how to use firebug:
- Open firebug
- Click on the Console Tab
- Reload the page
- Any https errors will show in the console and tell you which resource is not working.
Hope this helps