Unautheticatable updates

[Chris Jeffries]

Hey guys,

I just ran update manager as a result of some critical updates including
some linux header updates as below

adobeair (version 2.0.3.13070) will be upgraded to version 2.0.3.13070-0
chromium-browser (version 5.0.375.99~r51029-0ubuntu0.10.04.1) will be
upgraded to version 5.0.375.125~r53311-0ubuntu0.10.04.1
chromium-browser-inspector (version 5.0.375.99~r51029-0ubuntu0.10.04.1)
will be upgraded to version 5.0.375.125~r53311-0ubuntu0.10.04.1
linux-headers-2.6.32-24 (version 2.6.32-24.39) will be upgraded to
version 2.6.32-24.41
linux-headers-2.6.32-24-generic (version 2.6.32-24.39) will be upgraded
to version 2.6.32-24.41
linux-image-2.6.32-24-generic (version 2.6.32-24.39) will be upgraded to
version 2.6.32-24.41
linux-libc-dev (version 2.6.32-24.39) will be upgraded to version
2.6.32-24.41

Update manager says they cannot be authenticated.

I do not understand the authentication process, so I am not sure where
to start trying to track this down.

I have just started working through a VPN tunnel that drops me in UK
rather then natively connecting in China. I suspect it may be to do with
repositories - but before I start fiddling around, has anyone any
experience with the authentication of packages please.