Does your sources.list only contain security-entries?Add normal entries (deb http://ftp.XX.debian.org/ squeeze main contrib - where XX is for your country (us, de, fr, es...) and try again.
Am 11.04.2011 16:30, schrieb Andrew Wood:
My sources.list file contains: deb http://security.debian.org/ squeeze/updates main contrib deb-src http://security.debian.org/ squeeze/updates main contrib