I have four servers, one runs apt-cacher and I just upgraded this one to 12.04. I can update/upgrade it through it's own apt-cacher without error.

After the upgrade, I'm getting errors when doing apt-get update on the other machines.

One is running 10.04 and has these errors:

Err http://<serverIPaddress> lucid-updates Release.gpg
BAD HEADER FILE
Err http://<serverIPaddress> lucid/main Packages
Sub-process /bin/bzip2 returned an error code (2)
Another is also running 10.04 and has this error:

W: A error occurred during the signature verification. ... etc

The third is running 8.04 and has NO errors.

Can anyone suggest how to resolve these? They both happened since the upgrade of the apt-caching machine. Are they local errors or caused by the cache?