incomplete list of project branches?

This seems like such an obvious problem that I have no doubt I am missing some fundamental concept required for managing projects on launchpad. So.. I'm sorry!

I have a project in launchpad: lp:mmoss

I created branches: lp:~ericd-netdenizen/mmoss/dev (for doing development)
and lp:~ericd-netdenizen/mmoss/sandbox (for experimenting with bzr, etc.)

I have been developing the /dev branch for the past week and then I successfully merged its latest back into the main trunk. So that all seems fine.

What is puzzling me is that if I go to the mmoss project page on launchpad, and click the code "tab" the site shows me the main trunk branch and the sandbox branch but there is no sigh of the /dev branch whatsoever. The branch is there because I can pull it up by directly naming it in the URL: https://code.launchpad.net/~ericd-netdenizen/mmoss/dev.

What obvious point am I missing?

EDIT: I noticed its status was "merged", but I don't recall setting that status. Would its status automatically become merged if I merged it back into the trunk using bzr? In any case, I set the status back to "development" and it is again visible. I'm sorry for asking questions that I feel I should be able to answer by reading the docs, but it's hard to tell when I should stop searching and just ask someone.

-Eric