Google Presentation: "What Google Knows About Spam"

For a good 9 months my site was on pages 1-3 for all of my keywords & phrases. All of a sudden my SERP ranking was getting worse. After 3months, my site was no where to be found. I attributed it to having the same Title & Description info on every web page. After reading Forums, SEO Newsletters & SEO Sites, I attributed my ranking problem was due to that. I totally revamped by site and researched keyword phrases & keywords & changed the Title & Description info for every webpage. I started wondering why 3 of my competitions websites were above mine in the SERPs for the same Titles & Descriptions. I looked at their code and found 4 lines of hidden Title Text in each site. I reported them to Google: http://www.google.com/contact/spamreport.html and then reported them to Yahoo: http://help.yahoo.com/l/us/yahoo/search/spam_abuse.html. It appears that nothing was done to reprimand them as they are still on page 1 for most keyword phrases. How many times do they need to be reported and how does Google pick & choose who they are going to pull off the SERPS for not following SEO Practices? Thank you, Marian - http://www.CabinsPlusMore.com