[sniperhiga]

I am tired to hear from webmasters questions like "Why my positions dropped in 1 day?". Most of them believe that their website was punished for something.
In most cases, positions drop happen because Google change algoritm and change values of links, pagerank, content, and other factors. It mean, that google never punished your site, your site became a victim of changes which Google (or other search engine) maid to improve results.
How to protect:

Once you got good positions and traffic, you should go back and analyze how you promoted your site.

For example.
1) You submitted your site in 500 directories and wrote many articles. In this case you can drop if Google will decide to decrease value of directory links.

In this case change your stategy and avoid future directories submission, get some links from forums, find bloggers to link your site, exchange some links, get highter pr links, find content links etc...

2) You bought many links from hight Pagerank sites and they mostly located in the footer, or with other sponsored links. You can drop if Google will decide to decrease pr value a little and concentrate on content and anchor.

In this case, do some directories submission, article, forums, bloggers etc....

Remember... to avoid drops, you should have all types of links with different anchor from different sites.