hpgray on "[Plugin: WordPress SEO by Yoast] Alt tags for images"

WordPress version: 3.5
WordPress SEO version: 1.3.4.1

I did this: Give alt tags to the pictures

I expected the plugin to do this: Give me a green light for alt tags

Instead it did this: Give me a red for alt tags and told me I need them.

My pictures are being used in a WP-Ecommerce store. I have the pictures titled and alt taged, but the SEO tool is telling me I need to add tags. Thoughts?

http://wordpress.org/extend/plugins/wordpress-seo/