Comments Plus – Comment not posting to Facebook users wall

I have Comments Plus installed on a single wordpress site but though the comment posts on the WP site it does not post to the facebook wall of the user.

I followed all of the steps with creating the Facebook App – the only issue I cam across is that the domain name would only accept http://www.mydomain.com not http://www.mydomain.com/news which is where the WP site is set.

I’m using this plugin on 4 separate sites (not wpmu sites) under the one domain, so all under sub-directories. Could this be an issue?