Okay, it seemed that your hCard plugin worked when I did as you recommended; namely entering the URL where my hCard was located. That did fill in the forms. Not sure why the „Website“ field was filled out „http://Array“ (no quotes, however.)

The original comment was not posted, however when the browser refreshed I was „Welcomed back“ and apparently logged in to your site (via OpenID I presume?)

All in all seems a bit clunky, but I do like the working concept of the hCard filling in stuff from a central source that I control.