squid 配置 Basic auth 始终失败，百思不得其解

最近要用 squid ，并且要带密码认证

前两天试着搭建成功过，但是因为机器原因，配置文件丢失，今天按照同样的步骤重新配置之后每次启动都会提示
helperOpenServers: Starting 0/5 'basic_ncsa_auth' rocesses
helperOpenServers: No 'basic_ncsa_auth' processes needed.

用的是 http://www.cyberciti.biz/tips/linux-unix-squid-proxy-server-authentication.html 的步骤，和之前一样的

配置文件：
acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
acl localnet src fc00::/7 # RFC 4193 local private network range
acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged ) machines

acl SSL_ports port 443
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 # https
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl CONNECT method CONNECT

http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost manager
http_access deny manager

http_access allow localnet
http_access allow localhost

http_access deny all

https_port 9000

auth_param basic program /usr/lib64/squid/basic_ncsa_auth /etc/squid/users
auth_param basic children 5
auth_param basic credentialsttl 2 hours
acl Admin proxy_auth REQUIRED
http_access allow Admin
http_access deny all

coredump_dir /var/spool/squid

refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern . 0 20% 4320

/etc/squid/users 这个文件是存在的，经过测试有效，内含 Admin 用户密码信息

除了开头提到的一句提示以外无任何错误信息，折腾一天，换了不同机器，不同版本，百思不得其解，到底哪里错了？...