Looks like there's a bug in the Acquia Marina Theme. If I have all the blocks on the right then the green banners and white boxes don't work. A single block on the left makes both sides work.
I've applied the new Acquia Marina theme to the site. It looks good but looks better in the preview picture:
<img src="/images/acquia_marina.thumbnail.png" alt="Drupal Acquia Marina Thumbnail"/>
I can't work out where the white boxes with the green title bars surrounding the blocks have gone. Firebug is telling me that they are being overridden but that's not something to look at tonight!