Thanks Tom for your reply. I forgot to mention one point in my question - I used to rank for 'trash bags' somewhere by #13 and after I optimized the website to rank for that term it hasn't seen the daylight.

Does that change the question a bit?

I am trying to rank for the keyword "trash bags" I did  a lot of on-page optimization and link building. We started ranking #2 on bing and yahoo but google seems to be stubbornly fluctuating between being as high as 20 and as low as 45 and even dropped our rankings for a couple of weeks. Is there any need for concern if google is acting so different from bing/yahoo?

I found many duplicate title tags and I'm in the process of changing it  Do I need 301 redirects in place when I switch it? I am only changing the title tag.

Also, we are switching over to a new site very soon, I am worried that we might be using too many 301 redirect "hops" because we are doing a lot of optimization as well. (video from matt cutts describing 301 redirects and hops: http://www.youtube.com/watch?v=r1lVPrYoBkA.

Does anyone have any experience in doing too many redirect hops that it affected your rankings? Any good ideas to avoid this?