I have a site which got hit by Penguin like many others. It's a health-related WP blog placed in the folder like domain.com/apple-product-reviews. The site have about ten pages which have title like 'ipod reviews', 'iphone reviews', 'ipad reviews', 'macbook reviews' ... and their permalinks are exactly the same, these titles are also my targeting keywords. I list all these pages on the sidebar of blog. Therefore, each page have 2 words review or reviews in the title (something like iPad review | Apple product reviews) and also have 2 words reviews in the page's URL (domain.com/apple-product-reviews/ipad-review/). So do you think the word 'review' is stuffed in my site from Google's point of view ? Hence it is reason i got penalized ? The backlinks are not high quality links but they have good anchor text variation.