Update manager still searches for proxy even after disabling it

I had a proxy setting in Synaptic Package Manager, where it used to work properly. Currently I'm outside the proxy periphery and connecting directly to internet, hence changed the network settings in Synaptic, where the directly connect to internet is selected. However, while I try to run the update manager I still get the errors:

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy/Release.gpg Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy/main/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy/restricted/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy/universe/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy/multiverse/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy-updates/Release.gpg Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy-updates/main/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy-updates/restricted/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy-updates/universe/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/hardy-updates/multiverse/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://archive.canonical.com/ubuntu/dists/hardy/Release.gpg Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://archive.canonical.com/ubuntu/dists/hardy/partner/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://dl.google.com/linux/deb/dists/testing/Release.gpg Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://dl.google.com/linux/deb/dists/testing/non-free/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/hardy-security/Release.gpg Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/hardy-security/main/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/hardy-security/restricted/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/hardy-security/universe/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/hardy-security/multiverse/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://packages.medibuntu.org/dists/hardy/Release.gpg Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://packages.medibuntu.org/dists/hardy/free/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Failed to fetch http://packages.medibuntu.org/dists/hardy/non-free/i18n/Translation-en_IN.bz2 Could not resolve 'iiscproxy1.serc.iisc.ernet.in'

W: Some index files failed to download, they have been ignored, or old ones used instead.
W: You may want to run apt-get update to correct these problems

Can you give an idea, where else should I change the settings to get rid of the proxy ??
Thanks in advance ...