To make sure you have the right sources in your sources.list in /etc/apt/-folder open up emacs and see if the file contains the following:
deb http://archive.gnewsense.org/gnewsense-metad/gnewsense metad main deb-src http://archive.gnewsense.org/gnewsense-metad/gnewsense metad main ## gnewsense security deb http://archive.gnewsense.org/gnewsense-metad/gnewsense-security metad main deb-src http://archive.gnewsense.org/gnewsense-metad/gnewsense-security metad main