Branch drop down menu in repository tab of build plan doesn't show all branches

I am trying to select a branch as the default branch of a GitHub repository I want to include in a build plan. Not all branches show up in the drop down menu. More importantly, the branches I want to select does not show up in the drop down menu.

This only happens on repository with many branches (in this specific case, > 50)

Other Bamboo UI elements (e.g. during Project creation) find the missing branches fine.

This is preventing us from building our projects and gating the roll out of Bamboo to our team.

Screenshot at: https://www.dropbox.com/s/wcr9xrxqw6kso41/Screenshot%202014-05-01%2017.28.59.png