I have 2 urls http://www.sem-consultant.com/ and http://www.sem-consultant.com/index.html will this cause duplicate content and cause ranking to disappear I lost rankings which I had for Good keywords terms..
Short answer YES? Does it have a sever impact probably not, but you can solve the problem with PROPER site linking and a 301 redirect! If you need help let me know I can help you with the .htaccess stuff (for free obviously).