autenticacao no squid pai

Estou tendo erro 407 (accesso negado por falha de autenticacao) no squid pai.
Tenho q usar um proxy pai (q pede por autenticacao) e um proxy filho numa fabrica local com intencao de poupar banda.

sobre estas circunstâncias, tudo roda OK:
1º no filho adicionando linha 'cache_peer 172.17.50.2 parent 3128 3130 login=login:pass no-query default", tudo roda OK, mas é indesejável, pq sempre assumirá o mesmo usuario/senha;
2º no pai, desabilitando autenticacao, tudo roda OK, entao o problema está na autenticação...;
3º no navegador cliente (Internet Explorer), seto proxy pro pai, pede por usuario/senha e autentica OK, entao o problema nao esta na autenticacao nem nas permissoes dos arquivos de autenticacao.

Estou usando RedHat 9 com squid 2.5-STABLE1.2 nos dois proxys. O cliente navegador estou usando IE do Win Server 2003.

alguma sugestao?!?!? já postei em vários foruns e não obtive nenhuma resposta...


[CHILD]
http_port 3128
icp_port 3130
dns_nameservers 172.17.50.1 172.17.50.2
udp_incoming_address 0.0.0.0
udp_outgoing_address 255.255.255.255
cache_peer 172.17.50.2 parent 3128 3130 default
hierarchy_stoplist cgi-bin ?
acl QUERY urlpath_regex cgi-bin \?
no_cache deny QUERY
cache_mem 8 MB
cache_swap_low 50
cache_swap_high 90
cache_dir ufs /var/log/squid 16 4 4
cache_access_log /var/log/squid/access.log
cache_log /var/log/squid/cache.log
cache_store_log /var/log/squid/store.log
cache_swap_log /var/log/squid/swap.log
mime_table /etc/squid/mime.conf
debug_options ALL,1
log_fqdn off
client_netmask 255.255.0.0
acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl SSL_ports port 443 563
acl Safe_ports port 80 21 443 563 70 210 1025-65535
acl CONNECT method CONNECT
acl cliente src 172.17.0.0/255.255.0.0
acl parent dst 172.17.50.0/255.255.255.0
http_access allow localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access deny !cliente
http_access allow parent
http_access deny all
icp_access allow all
miss_access allow all
cache_mgr [email protected]
cache_effective_user squid
cache_effective_group squid
visible_hostname child.cq.xxx.com
unique_hostname child.cq.xxx.com
logfile_rotate 10
append_domain .cq.xxx.com
#never_direct allow all
error_directory /etc/squid/errors


[PARENT]
http_port 3128
icp_port 3130
dns_nameservers 172.17.50.1 172.17.50.2
udp_incoming_address 0.0.0.0
udp_outgoing_address 255.255.255.255
hierarchy_stoplist cgi-bin ?
acl QUERY urlpath_regex cgi-bin \?
no_cache deny QUERY
auth_param basic program "/usr/share/./ncsa_auth" "/etc/squid/passwd"
auth_param basic children 5
auth_param basic realm Digite seu login
cache_mem 8 MB
cache_swap_low 50
cache_swap_high 90
cache_dir ufs /var/log/squid 16 4 4
cache_access_log /var/log/squid/access.log
cache_log /var/log/squid/cache.log
cache_store_log /var/log/squid/store.log
cache_swap_log /var/log/squid/swap.log
mime_table /etc/squid/mime.conf
debug_options ALL,1
log_fqdn off
client_netmask 255.255.0.0
acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl SSL_ports port 443 563
acl Safe_ports port 80 21 443 563 70 210 1025-65535
acl CONNECT method CONNECT
acl rede_local src 172.17.0.0/255.255.0.0
#acl child src 172.17.50.1/255.255.255.255
acl autenticacao proxy_auth REQUIRED
#acl parent dst 172.17.50.0/255.255.255.0
#acl http dst 172.17.50.2/255.255.255.255
#acl local src 172.17.50.2/255.255.255.255
http_access allow localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow rede_local
http_access allow autenticacao
http_access allow rede_local
http_access deny all
icp_access allow all
miss_access allow all
cache_mgr [email protected]
cache_effective_user squid
cache_effective_group squid
visible_hostname parent.xxx.com
unique_hostname parent.xxx.com
logfile_rotate 10
append_domain .xxx.com
#never_direct allow all
error_directory /etc/squid/errors