Welcome to the Q&A Forum

With your SEOmoz membership, you can ask one question a month in private Q&A, and get it answered by an SEOmoz Staff or SEOmoz associate -- the questions are not indexed, are private, and everyone is under an NDA to not disclose the contents of the question. When you ask a question, look at the bottom of the submission form and there is an option to ask it as a private question.

The above rel canonical on the page is perfectly fine. They should not be reason for your ranking drop and can be left untouched. However, make sure that all pages have canonical set as respective page URLs. These are generally added give a directive to search engines about the one version of URL to be indexed. Reasons for the same can be numerously like reducing duplicate content on the site (especially ecommercce site) to ensuring the link value passes to main URL where people link to your pages using utm parameters. You can read more about canonical tags here: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=139394