I've been having a heck of a time trying to figure out my "some items on this page are not secure" issue and ran across this plugin which I was hoping was my savior. Unfortunately I'm still seeing the same errors.
I only have SSL setup on my Checkout pages. If you want to test it go to this page http://612.mn/deals/15-for-25-best-buy-gift-card-limited-quantity/ and click Buy Now and then click Checkout. You'll then see the errors.
The issues I'm seeing are a few parent theme style.css issues and a sharethis plugin button.
Any help would be appreciated. I have your plugin actively running on the site.