http://cdimage.debian.org/debian-cd/4.0_r6/i386/iso-cd/
You might also want to check out the Netinstall of Etch-n-half
Its an updated installer and some updated packages...my guess is to bridge the divid between older and newer hardware..
EtchAndAHalf Wiki
http://wiki.debian.org/EtchAndAHalf
The EAAH (Etch And A Half) netinst image enabled me to load Debian, but booting is still an issue.. timeouts on certain ATA commands/channels (ata2) and then after attempting a 2nd boot I get told my root partition's mount point doesn't exist.
still better than just sitting there with no valid cdrom detection. LOL