my this site:- http://www.shainex.com/ lost the ranking again in Big G, what to do to get the stable ranking for keywords? Please help..
It's the SERP reflux it happens once per month 1-4 days or something like this ... but your the SEO "experts" lol ) fail ...
Your signature says that you deal with SEO service. Anyways, you need your service of SEO to get your keyword in a good position.
You need to continue the link building, the ranking fluctuates because you might not be having enough backlinks.
Keep on building quality back links, this ranking getting down keeps on happening, do not stop doing good SEO.
create more relevancy for that keyword and as w3bmaster said later on this thread it may be minor fluctuation in Google SERPs.
Tons of duplicate content resting on your website is the reason for fall of your website. Wipe out all the content before Google slapped you any penalty or ban.