So far remembering the password for flickertcb-devel has proven more than my feeble mind can muster. Compounding this problem is that there is no obvious action to be taken (e.g., a Forgot Your Password? link) from the Mailman page that requests this password. Here is what to do (current as of the time of this post anyways; SourceForge has been making some design changes):
Sign in and go to your SourceForge project’s administrative home page. From the “Project Admin” drop-down menu, select the “Features” item. At the far right of the “Mailing Lists” row in the ensuing table, select “Manage”.
The three options below the list’s Description field are: “Mailman Admin | List Subscribers | Change Password”. Change Password does the trick.