Xml-rpc for wordpress 2.1.1 and performancing


I recently stumbled upon the PerFormancing extension for Firefox, and I thought all would just work out of the box. It is a integrated posting extension that takes advantage of xml-rpc to post. Currently it is giving me the error “Failed to Log in” when trying to add the blog to the extension. Does anyone know a work around (manual configuration doesn’t change anything) or a way to help debug this? Even another nice and similar extension would be appreciated.