I thought that my Live Labs Managed Card was missing claims, which was preventing the CardSpace UI from sending the card to the site.
Turns out that I was using the wrong token type - so far my self issued cards have been using SAML 1.0 tokens, whereas the Live Labs STS required SAML 1.1 tokens.
I've updated my system to allow the TokenType to be configurable, so now you can choose the token type for each DNN portal.
Managed Cards are still not ready, I'm waiting on an update of the TokenProcessor from Microsoft that will allow the Live Labs STS cards to be used.
Stay posted..