I have the same problem. Also, I get a lot of missed package definitions when I run apt-get update:
W: Couldn't stat source package list http://deb.plutohome.com replacements/non-free Packages (/var/lib/apt/lists/deb.plutohome.com_debian_dists_replacements_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://deb.plutohome.com replacements/contrib Packages (/var/lib/apt/lists/deb.plutohome.com_debian_dists_replacements_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://deb.plutohome.com replacements/non-free Packages (/var/lib/apt/lists/deb.plutohome.com_debian_dists_replacements_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://deb.plutohome.com replacements/contrib Packages (/var/lib/apt/lists/deb.plutohome.com_debian_dists_replacements_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Duplicate sources.list entry http://deb.plutohome.com 20dev/main Packages (/var/lib/apt/lists/deb.plutohome.com_debian_dists_20dev_main_binary-i386_Packages)
W: Duplicate sources.list entry http://deb.plutohome.com replacements/main Packages (/var/lib/apt/lists/deb.plutohome.com_debian_dists_replacements_main_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems
E: Some index files failed to download, they have been ignored, or old ones used instead.
My /ets/apt/sources.list file contains following:
# Pluto sources - start
deb file:/usr/pluto/deb-cache/ sarge main
deb http://deb.plutohome.com/debian/ 20dev main
deb http://deb.plutohome.com/debian/ replacements main
deb http://deb.plutohome.com/debian/ sarge main non-free contrib
deb http://deb.plutohome.com/debian/ unstable mythtv
deb http://www.yttron.as.ro/ sarge main
# Pluto sources - end
deb http://deb.plutohome.com/debian/ replacements main non-free contrib
deb http://www.yttron.as.ro/ unstable main
deb http://www.yttron.as.ro/ realextra main
deb http://deb.plutohome.com/debian 20dev main