Further investigation when this popped up again shows the same behavior using apt from the command line, suggesting that is where this bug lies. (This time there is also no wine package in the updates to be installed). Again, running "apt-get update" to refresh the lists solves the problem and all packages are detected as signed.
apt 0.6.45ubuntu5 -- All updates show up as "Not Authenticated" when only one is. https://launchpad.net/bugs/31706 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
