One of my site is frequently disappearing and coming back in Google. After holding 7th position in Google for a month and half it disappeared on 6th June 2011. It reappeared on 21st June and was in 3rd position. Then disappeared again on 6th July. Reappeared on 15th July as 2nd on Google 1st page, right after an EzineArticle published and I bookmarked it. Now it disappeared again on 19th July.
I am confused. Anyone can explain me the possible reason! Is it coming back! Anything I can do for that?