Comment 0 for bug 389001

The timeout option being used in smart is about the whole lifetime of the connection, regardless if it's idle or not. If you are downloading a big package over a slow link, it can kill your download:

Failed to download packages:
    http://security.ubuntu.com/ubuntu/pool/main/o/openssl-blacklist/openssl-blacklist_0.3.3+0.4-0ubuntu0.8.04.3_all.deb: Operation timed out after 600000 milliseconds with 5884564 out of 6333180 bytes received

In the example above, the download was still active, i.e., bytes were being transferred.