Inserting image in product post.

I have been using the two images (featured and post thumbnail) for products at my online store. I use WooCommerce, and it has been going well, except for this little annoyance.

The featured image becomes the main image for the product, and the post thumbnail (“insert into post”) becomes the alternate image (a smaller thumbnail under the main picture) as well as a picture in the product info section (the body of the post). Check out an example, at http://electronic-smoke-shop.ca/smoke-shop/joyetech-510-manual/ , to see what I mean exactly.

Anyway, this worked for the longest time… and now it stopped working.

Now when I insert an image into my post, it places it in the product info section (the body), but there is no thumbnail underneath the featured image. Why is that?

I haven’t installed any plugins lately, and I don’t think anything has changed with WordPress or my computer. So I am confused!

And I have just shot new pictures, and I am looking to update my whole store. Can someone help me with this issue?

Thanks a bunch!