Help with Blog Spam Content added by non registered users ?

Hi,

I have a dev site here http://www.cloud-webdesign.co.uk/ and even though I have turned off users from registering, I am getting SPAM blogs being posted by numberous users. There are only TWO accounts / official users, and there are two many of these fake users to delete.

How can users who have not registered SPAM blogs without accounts ?

Any help appreciated.... btw I have also activated HYPESPAM and various other anti spam techniques, but none seem to stop this activity... do I have some other vunerabilities I have left open ?

Help appreciated.