Your site is throwing javascript errors as you can see if you use the error console or Firebug. The first issue is that your WP theme (I believe it is the theme) is loading the JQuery library from the Google CDN. This SP codex artivcle explains the problems with this: http://codex.simple-press.com/codex/faq/troubleshooting/what-is-this-jquery-conflict/

A really nice theme author will give you the chance to turn this off. If that is not the case then you will need to find where it is being loaded and we will need to change it. It s usually a very easy fix.

When that is fixed we can see if the script error is still being seen and fix that up as well but it may well be related.

Ok fixed the jquery issue.  Add topic is working fine now!

Thanks.