Comment 68 for bug 154771

I had the same problem. I started with 7.04, upgraded in early October, then kept getting bugged about upgrading every day.

In what seemed to be an unrelated error, I also noticed that I was getting the following error message when I did a "sudo apt-get update":

Fetched 81.7kB in 0s (259kB/s)
Reading package lists... Done
W: GPG error: http://security.ubuntu.com gutsy-security Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>
W: GPG error: http://us.archive.ubuntu.com gutsy-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>
W: You may want to run apt-get update to correct these problems

So I googled around a bit to find a solution to this problem and found this solution:

# Retrieve the ubuntu key with wwwkeys.eu.pgp.net, store it in my keyring
gpg --keyserver wwwkeys.eu.pgp.net --recv-keys 437D05B5
# Add the retrieved key along with other existing keys
sudo apt-key add ~/.gnupg/pubring.gpg
# apt-get update without cache to force the use of the newly added key
sudo apt-get update -o Acquire::http::No-Cache=True

In my case, I had to change the ownership of ~/.gnupg/trustdb.gpg from root to myself. But the key import worked fine and this fixed the bad apt-get key problem. When I did another "sudo apt-get update" and "sudo apt-get dist-upgrade", suddenly it found more updates:

alan@chutney:~$ sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  adept adept-batch adept-common adept-installer adept-manager adept-notifier adept-updater firefox
  ghostscript ghostscript-x gs-esp-x kdelibs-data kdelibs4c2a libgs8 libssl0.9.8 mozilla-thunderbird openssl
  thunderbird
18 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 46.6MB of archives.
After unpacking 28.7kB of additional disk space will be used.
Do you want to continue [Y/n]?

Notice that several "adept" changes are included above.

I am still installing these changes right now, so I can not verify that this fixes the update-daily problem, but it is consistent with what others are seeing: you keep getting pestered until adept is updated -- and something is holding adept back. In my case, it looked like it was the keys.

Alan