Error : Cache Access Denied

I have installed Squid proxy 2.7 on windows 2008 servers with RADIUS.

while accessing (on client) for Internet from Windows XP/Windows 7 , I got following error
User name : xyx@proxy.com
Password : XXXXXX
ERROR
Cache Access Denied

While trying to retrieve the URL:http://www.google.co.in/

The following error was encountered:

Cache Access Denied.

Sorry, you are not currently allowed to request:

http://www.google.co.in/

from this cache until you have authenticated yourself.

My Squid Proxy Config file is like this


auth_param basic program c:/squid/libexec/squid_radius_auth.exe -f /etc/radius_config
auth_param basic children 5
auth_param basic realm XYZ : User Credentials
auth_param basic credentialsttl 5 minute
auth_param basic casesensitive off
acl radius_auth proxy_auth REQUIRED
http_access allow radius_auth




squid_rad_auth configuration file

server 192.168.1.57
#secret test




Pl Help me , how to solve this problem.