I am using php-cgi lines in the files, this is a fresh install of 2.9.2 and so I am using the default theme and no plugins. When I am logged in as an admin I can post the comments, but when someone else tries to comment, the error message displayed is 500. However, when I go back to the post and refresh I see that the comment is posted. So I think it is the redirect(after commenting) to the post is not happening. What could be going wrong, please suggest. I have tried to empty DB(as it was a fresh install) and even tried to reinstall; but nothing helps.