Page is a not externally linkable
-- Google SEO News and Discussion
---- Google Updates and SERP Changes - November 2012
Shepherd - 2:49 pm on Nov 20, 2012 (gmt 0)Thread source:: http://www.webmasterworld.com/google/4515090.htm
Based on how are sites were affected it appears to have been a penguin related update. Out sites/keywords were affected in the same manner and for the same keywords that they were hit for in April.
Brought to you by WebmasterWorld: http://www.webmasterworld.com