apt-get update error with backports

[Leonardo Carneiro - Veltrac <lscarneiro@veltrac.com.br>]

Title: Leonardo de Souza Carneiro

For some weeks now i'm getting the following error when i try to do a apt-get update:

W: Falhou ao buscar http://backports.org/debian/dists/lenny-backports/main/binary-i386/Packages.bz2  Hash Sum incorreto

E: Alguns arquivos de indice falharam para baixar, eles foram ignorados ou os antigos foram usados no lugar.

Translated:

W: Failed to fetch http://backports.org/debian/dists/lenny-backports/main/binary-i386/Packages.bz2  Hash Sum incorret

E: Some index file fail to download, they have been ignored or the older have been used instead.

Any clues? Tks in advance and sorry for my poor english.

--
Leonardo Carneiro