404 errors for install image links

["Geoff Midler" <gmidler@gmail.com>]

 On http://www.debian.org/releases/stable/debian-installer/ , the links to amd64 images return 404 Not Found errors. Checking out 
http://cdimage.debian.org/debian-cd/3.1_r5/ shows that no /amd64/ directory exists? 

http://cdimage.debian.org/debian-cd/3.1_r5/amd64/iso-cd/debian-31r5-amd64-netinst.iso
http://cdimage.debian.org/debian-cd/3.1_r5/amd64/iso-cd/debian-31r5-amd64-businesscard.iso
http://cdimage.debian.org/debian-cd/3.1_r5/amd64/iso-cd/  --> 'Full CD sets' link
http://cdimage.debian.org/debian-cd/3.1_r5/amd64/bt-cd/
http://ftp.debian.org/debian/dists/sarge/main/installer-amd64/current/images/



Also, the section in 
http://www.debian.org/ports/amd64/ stating:
  "To install Debian GNU/Linux 3.1r5
(sarge) on AMD64 systems, download any of the following images:
netinst CD image (100 Mb)"
 is a link to the iso for 31r4 (
http://cdimage.debian.org/cdimage/unofficial/sarge-amd64/iso-cd/debian-31r4-amd64-netinst.iso). 

Thanks.