deborahbaker - 8:29 am on Nov 4, 2012 (gmt 0)

I have a very well established site which has been live since around 1996. It was on page 1 of google for many keywords normally in position 1 in a not really competitive market. It is the ultimate site for its topic.

In march this year I changed the site structure. Initially it was a landing page eg www.mydomain.com with cube cart in a folder called 'store'. With a few old established htm pages to beef it up.

I decided to get rid of the htm landing page and move the store home page from mydomain.com/store/index.php to mydomain.com/index.php. I set up redirects through .htaccess to keep the back links and page rank.

Since then the site has gradually dropped in the rankings and visitors have dropped from 7000 unique to 1300 unique. I checked all my files and noticed that I had not altered my robots.txt file which was stopping spiders accessing folder /images/. Which originally was just images but of course when I restructured the site this folder then became one with lots of functional cube art files in it. So I thought that that was the reason. I have changed the robots file to give the spiders full access.

My questions are

1. Does anyone know if the robots file could have caused this to happen?
or
2. Should I move the cube cart files back to their original position in the site structure and put back the htm landing page as it was probably more seo friendly. Do you think a htm home page is a better seo option than the cube art index.php page?
Or
3. Could it be something else I have not thought of? It just seems too coincidental as the site has had these positions for 20 years and was not affected at all by penguin or panda

Any help would be really appreciated
Thanks