Sales and website visits droppped since upgrade to 1.5.4.1

[judy_t_judy]

I upgraded to the new version 1.5.4.1.Since the upgrade i have had no sales on my prestashop shop.My visits to the website through other links like google etc have dropped significantly and i have no idea why.My stats were really inflated and i know these are all incorrect since the majority are direct link visits.I recently started working on SEO and added the robots.txt file but i ended up with over 1000 phantom carts.Has anyone else having this problem.Please let me know how to fix this .