I desctibed the detail information about the installation error in bug report 279508. The install image which I used is "sid-amd64-netinst.iso" that was acquired from "http://debian-amd64.alioth.debian.org/install-images/2004-10-22/";. The error will occur either express method or expert method. I can not install Debian AMD64 on my PC whose motherboard is Tyan S4880.