Something is slightly hosed in my update process. I tried to use the Update Manager or apt-get update, and I get a notice that I have a bad signature. I think it is related to VirtualBox. Anyway, here is the response I get with apt-get update:
Reading package lists... Done
W: GPG error: http://us.archive.ubuntu.com lucid Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email@example.com>
What do I do to fix this?