The description of the Comodo secure DNS at http://www.comodo.com/secure-dns/ has different information in the text paragraphs as compared to the right instructions, specifically different addresses for the secondary server. The text still has a 156. and the instructions two 8. ones. Switch Now - Change to Comodo Secure DNS Service shows the 8. ones.
Suggest Comodo have a better look at their informational QA as they update things.
The page shows both one of the new and one of the old in case the newer would have a problem you’d have an old to fall back on.
At computerflyer. I split your post and moved it to the Report Comodo Forum / Web Site Issues board.