I personally had about 5 or so Astores ranking in the top few results for the last year, but 2 days ago they all dropped about 5 pages in Google. Thought it was maybe something I've done, but then I had a little search for some other peoples Astores that I know rank top and they had all dropped about 5 pages. I take it other people are experiencing this too? Fingers crossed Google is just messing around and things will bounce back soon.
Did you have any content on the astore? Guides, articles etc? Google doesn't like astores much but maybe if you added a lot of content might help to get back or build a store using a script that makes it easy to add content and make it uniqe.
Like I say, my stores was ranked number 1 for well over a year, closer to 2 years. I'm not looking for your advice on getting sites ranking, i'm just pointing out that Googles algorithms have changed in the last couple of days.