Cannot submit comment

http://wordpress.org/extend/plugins/redirection/

I am using redirect plugin to redirect my old URLs from /blog/ to /
I have my core files in /blog but blog URL is set to root and wordpress address URL is set to /blog. The index file in the root has require(‘./blog/wp-blog-header.php’);
I am using Permalinks as /%category%/%postname%/
The posts appear fine but when I submit a comment, I get “Oops! This link appears to be broken.”