if this behavior is by design, I will anyway suggest to log the error somewhere (syslog?).
I have had lost a lot of time figuring out what the matter was.
If pam_motd had has logged the error, I would have solved the issue in a fraction of time.
Dustin, it isn't cpu-checks related.
During the upgrade I lost the update-notifier-common package and, with it, a lot of scripts (included the cpu-checks script).
Thanks you all for your great work on Ubuntu!