Does not auto update

I have a development set up with this Beta Tester plugin activated, set to Bleeding Edge nightlies.

(I also have http://pento.net/projects/automatic-updater-for-wordpress/) installed.

I have some themes and plugins (version controlled) that I want to test and develop against the these nightlies.

However, nothing auto-updates.

http://wordpress.org/plugins/wordpress-beta-tester/