Hi Nick,
Sure, URL: http://www.duesoon.com.au/store/pregnancy-pilates/ and keyword phrase 'Pregnancy exercise dvd'. I have tried this tool using various URL's from my site as well as keywords and receive the same error message. I am very new at SEO stuff and we are currently employing our web developer to work on some major keywords for us. I am trying to broaden my SEO knowledge so that I can upload new products and content in a google friendly way, and so that I can identify and target other keywords in the future. Our domain is hosted on our webdevelopers server, so I wonder if the comment Valery made regarding the server blocking the MozBot could be the issue. I have contacted our developer to check.
I very much appreciate everyones help and suggestions as well as the excellent tools and information provided by SEOMoz!