Sgt_Kickaxe - 6:29 am on Nov 14, 2012 (gmt 0)
Something else to keep in mind: content on page A can have a negative effect on the rankings of content on page B with Panda.
I've personally seen this happen to a site with affiliate pages. The owner had been well ranked for close to 8 years and had sailed through Panda and Penguin without any noticeable effect, until he added a new category to his site containing several affiliate reviews with offers.
The new pages didn't rank well and brought little traffic but the other pages, most of which were five or more years old, began to tumble in serps. Shocked he removed the content and asked for reconsideration but was told there was no penalty and roughly 90 days later his older content began rising in the serps again.
note: he didn't use robots.txt or add a redirect/meta tag to the pages, he simply ripped them out of the site and allowed them to return 404 errors.
My best guess: A site can support x amount of negative factors and remain boyant but x+1 and the site begins to suffer as a whole, not just on the pages with negative factors(eg aff links, thin content, unrelated content etc). All things in moderation!