taxonomies="tag" not showing working

First of all, what a great plug-in. This was exactly what I was looking for.
Unfortunately though, I can only find it to work with category as a taxonomy. Ounce I add a taxonomy like taxonomy=”tag” it shows no result on the page and also my footer will not be loaded.

Do you have any idea how te resolve this. I would love to implement this plug-in in my site.

http://wordpress.org/extend/plugins/ajax-post-filter/