[Plugin: WooCommerce – excelling eCommerce] [Plugin: WooCommerce] Product Attributes

unable to use global attributes (type:text) on a product variation?
trying to select a text attribute for a variable product does not save. It always expects you to enter a list of values, but this is not a drop down list, I want it to be a free text entry field?
why does this not work?

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