I’m having the same problem!!!!!
In fact, there seems to be a good few WordPress people having trouble! There’s no problem commenting on a WordPress blog, but when you try to comment on another blog site, the OpenID error keeps coming up!
so i went on openid and it seems that the openid that has always been associated with my blog is not registered. It then brought me to a page to create an openid, at which I would have to pay.. does this makes sense?