Problem installing cyrus22 on a debian sarge amd64

[Julien P.]

"Henrique de Moraes Holschuh" <hmh at debian.org> a écrit dans le message de 
news: 20060626121354.GF18441 at khazad-dum.debian.net...
> I believe these packages are now hosted as official backports in
> http://backports.org.   Update your apt source configuration.

I have exactly the same problem, when updating my sources.list with 
backport, then doing an aptitude update, I get the error:

W: Couldn't stat source package list http://www.backports.org 
sarge-backports/main Packages 
(/var/lib/apt/lists/www.backports.org_debian_dists_sarge-backports_main_binary-amd64_Packages) 
 - stat (2 No such file or directory)
W: You may want to update the package lists to correct these missing files
W: You may want to update the package lists to correct these missing files