[Plugin: WordPress SEO by Yoast] Plugin lying to me and failing to see stuff

Hi,

I have had great results with this plugin in the past and would like to keep using it, however it is not seeing my content. For example:

There are 1 words contained in the body copy. This is far too low and should be increased.

and

The keyword density is %, which is a bit low, the keyword was found 0 times.

No number, or anything – weird.
Clearly I have words (including the focus keyword, obviously) the plugin just goes west.

I dont know if the problem lies with the plugin or the theme. I am using the Etherna Theme if that helps.

I would really like to get this sorted please.

Thanks for any help

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