Hummingbird reports one of its own cached objects as a blocker

I've installed Hummingbird and when I look at the Render blocking section it reports:

None of the above-the-fold content on your page could be rendered without waiting for the following resources to load. Try to defer or asynchronously load blocking resources, or inline the critical portions of those resources directly in the HTML.

Remove render-blocking JavaScript:

http://tty.org.uk/wp-content/uploads/wp-hummingbird-cache/354b94b189367fddec57a938e4ea5184.js

Optimize CSS Delivery of the following:

http://tty.org.uk/wp-content/themes/twentyten/style.css

http://tty.org.uk/wp-content/uploads/wp-hummingbird-cache/f2be8d2785e7db70871409187e80e659.css

Why is it reporting that objects its created are blockers?