apt-get error - cannot install anything (2 replies)

any packages i try to install give me this error message:

root@GoFlexSqueeze:~# apt-get install wicd-curses
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package wicd-curses is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'wicd-curses' has no installation candidate
root@GoFlexSqueeze:~#

I ran apt-get update (output here) and still same thing

here is the output of cat /etc/apt/sources.list

root@GoFlexSqueeze:~# cat /etc/apt/sources.list
deb http://security.debian.org/ squeeze/updates main contrib non-free
deb-src http://security.debian.org/ squeeze/updates main contrib non-free
deb http://ftp.debian.org/debian/ squeeze main contrib non-free
deb-src http://ftp.debian.org/debian/ squeeze main contrib non-free