Tem mais algum repositorio oficial (seguro) que devo adicionar a lista?
#mirros de segurança
deb http://security.debian.org/ squeeze/updates main contrib
deb-src http://security.debian.org/ squeeze/updates main contrib
#mirros oficiais
deb ftp://ftp.br.debian.org/debian/ squeeze main contrib non-free
deb http://linorg.usp.br/debian/ squeeze main contrib non-free
#mirros multimidia
deb http://debian-multimedia.org/ testing main
deb http://ftp.debian-unofficial.org/debian testing main contrib non-free
#compiz-fusion
deb http://apt-get.if.uff.br lenny-ifuff compiz
#opera
#deb http://deb.opera.com/opera/ testing non-free
O que significa esse contrib non-free e main contrib?
