Apparently there was some big changes in the Google Algorithme recently. I wrote a post months ago about how to use the nofollow attribute for internal linking (PR sculpting): be aware that this is apparently changing and the use of NoFollow internally does not seem to be advised or accepted by Google.
See below a pic [...]

Just a quick reminder for the neophytes, there are 3 big families of criterias to work on in SEO:

Criterias On Page (Keywords on your page)
Criterias on Site (The structure of your website - internal linking)
Criterias Off Site (External linking)

This post will talk about criterias on site. I had observed many websites, and the criterias on [...]