[CentOS] need help to build livecd and create success iso file but it hang

Hi all

my environment:
      1/ windows 7 OS system
      2/ use virtual box install the host centos system


i try to make a centos livecd and i follow the step
1/ create  file: vi /etc/yum.repos.d/centos-livecd.repo and the content of file:
# Name: CentOS LiveCD repository
[livecd]
name = CentOS $releasever - LiveCD
baseurl = http://www.nanotechnologies.qc.ca/propos/linux/centos-live/$basearch/live
enabled=1
protect=0
gpgkey = http://www.nanotechnologies.qc.ca/propos/linux/RPM-GPG-KEY-PGuay2010
2/ yum install livecd-tools syslinux anaconda-runtime

3/ create file alochym.ks and content of file:
lang en_US.UTF-8
keyboard us
timezone US/Eastern
auth --useshadow --enablemd5
selinux --enforcing
firewall --disabled
repo --name=a-base    --baseurl=http://mirror-fpt-telecom.fpt.net/centos/5/os/$basearch
repo --name=a-updates --baseurl=http://mirror-fpt-telecom.fpt.net/centos/5/updates/$basearch
repo --name=a-extras  --baseurl=http://mirror-fpt-telecom.fpt.net/centos/5/extras/$basearch
repo --name=a-live    --baseurl=http://www.nanotechnologies.qc.ca/propos/linux/centos-live/$basearch/live
%packages
bash
kernel
syslinux
passwd
policycoreutils
chkconfig
authconfig
rootfiles
comps-extras
xkeyboard-config
openssh

4/ run command : LANG=C livecd-creator --config=/mnt/alochym.ks --fslabel=CentOS-mini

5/ download the file CentOS-mini.iso to windows 7

6/ use virtual box create new virtual machine with CentOS-mini.iso as cdrom

the log of create livecd : http://pastebin.com/Z5BFASXa

the problem is when i use the CentOS-mini.iso with new virtual machine and the virtual manchine hang when automatic boot to 0 second

can somebody help me

Thank you