Error in updates download due to invalid signature

[shailesh_paranjpe]

I have Kubuntu 64 bit oneiric installed on HP Pavilion DV6 AMD 64 bit processor.
When I try to download the software updates from Apper, I get the following error message:
===========================
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com><br><br>E: Error http://archive.canonical.com oneiric Release<br> <br>
=============================

Due to this, I am totally unable to download and apply updates. I don't have any knowledge in the signature validation etc. Please guide.

Thanks

[shailesh_paranjpe]

Re: Error in updates download due to invalid signature

Thanks for reply. The certificate error was shown by all package managers, Apper, Muon as well as aptitude. So the problem was not related to Apper. Any way, I checked with some previous posts on Kubuntu Forums as well as Launchpad and found the solution here:

https://answers.launchpad.net/ubuntu/+question/89018

The problem resolved by removing the old list and downloading a new one & updating.