I am having the same problem, but using ftp without a proxy (we have proxy authentication problems using http/apt here):
Reading package lists... Done
W: GPG error: ftp://au.archive.ubuntu.com jaunty-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>
W: You may want to run apt-get update to correct these problems
So, at least for this case it is not a matter of apt working around truly broken proxies. Pointing to other repos (ftp://mirror.internode.on.net/) results in no error.
I am having the same problem, but using ftp without a proxy (we have proxy authentication problems using http/apt here):
Reading package lists... Done archive. ubuntu. com jaunty-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>
W: GPG error: ftp://au.
W: You may want to run apt-get update to correct these problems
So, at least for this case it is not a matter of apt working around truly broken proxies. Pointing to other repos (ftp://mirror. internode. on.net/) results in no error.