Commit dropdown list sometimes can't fetch commit list in source tab (BB-8920)

When viewing a file source in the source tab, the commit-list button shows a dropdown, but sometimes fails to fetch the commit list, hangs on the loader.
Same goes for the commit lists when trying to diff files, still in the source tab.

Error shown in console : Uncaught TypeError: Cannot read property '1' of null

OSX 10.8.4 Chrome 28.0.1500.71