The underlying problem (which reappears again and again with every aspect of the Wii meeting the internet) is that instead of accounts/profiles, the Wii in itself is what points are recorded to and represents your identity. They can't just add some points to your account and knock some stars from the website, they have to go through the process of creating codes which credit your Wii by however many points.
Like in the factory when they make the cards with unique codes, the codes only become valid as they are created to stop people from simply cracking the system and making their own. This means that even if they aren't making a card and sending it to you, they have to make the codes in batches for security reasons.
They could properly integrate the two systems, but they've not bothered. Hence why you have to punch in a code, and why the 'cards' ran out.
It's so utterly retarded and lazy that my head is spinning and I probably won't sleep tonight for fear of being attacked by escaped Nintendo of Europe staff (who are zombies with no heads).
The completely randomized star expiration thing is just the icing on the cake.
And it doesn't even make any difference to me because I won't be able to register my account with my American Wii anyway!