I have big curious on this. After I done some SEO like find some new authoritative links or on-page optimization. My site ranking will be dropped a few spots (sometime 10 spots) and march in ranking and will happen again if I done some seo. Why ranking has to be like this? Why ranking just don't march up and up? I know already that ranking will be march up but when site ranking down that give my heart broken. Heart attacked issue
You and the rest of us That is the problem with being a webmaster and being bent over ready to get ******** by Google if its automaton robot brain thinks you have comitted an e-crime. Its not good for the health if you dont have strong nerves and a cold heart! The solution is to make your site successful enough so that it CANT be banned by Google or any of the SE's..... For example webmasterworld would never be banned due to the uproar it would bring and the fact it is so well known in the web community DP would not be banned or would be quickly re instated if anything did go amiss and as for ebay or paypal...well, it just wouldnt happen
The reason they down is your changing your site design and layout, which to Google flags a possible change in content. Remember, you site was ranked at its current position as is, any changes makes the crawl re-evalutate the site and its backlinks for the new content and\or design. This is the nature of search engine crawlers and should be expected.