Was experiencing similar behaviour in Synaptic on Jaunty.
Checked what would happen when using apt-get:
WARNING: The following packages cannot be authenticated!
---snip---
Authentication warning overridden.
So in my case it wasn't a Synaptic bug. Checked /etc/apt/apt.conf and
found
It may be worth checking whether there's an option to enable Cool 'n
Quiet in the BIOS. Such an option may have been disabled after a BIOS
upgrade.
This is discussed here for a different motherboard with similar symptoms:
http://ubuntuforums.org/showthread.php?p=7636364
--
BIOS does not provide
It may be worth checking that Cool 'n Quiet is enabled in the BIOS.
This is discussed for a similar motherboard here:
http://ubuntuforums.org/showthread.php?p=7636364
--
powernow-k8: Your BIOS does not provide ACPI _PSS objects in a way that Linux
understands
