Jaunty to Karmic upgrade problem

[arvin555]

After waiting several weeks, and freeing up disk space, I tried updating/upgrading my Ubuntu from 9.04 Jaunty to 9.10.

I opened the update manager and clicked on Upgrade button.

Then I got a message as below:



W:GPG error: http://archive.ubuntu.com karmic-backports Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>,

W:Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-updates/universe/binary-i386/Packages.bz2 Hash Sum mismatch
,
W:Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-updates/multiverse/binary-i386/Packages.bz2 Hash Sum mismatch
,
W:Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-proposed/main/binary-i386/Packages.bz2 Hash Sum mismatch
,
E:Some index files failed to download, they have been ignored, or old ones used instead.

I have not tried to do a clean install, I'm a bit afraid I might lose some programs and settings that others have reported to have been having problems after the upgrade/install.

If ever I do decide to jump in and upgrade, can anyone please inform me what the error message means and more importantly how I can fix it? or should I just do an install instead of an upgrade?

Or is there a way to manually upgrade?

Thanks in advance. :)

TTFN
Arvin