AD SSO with auto proxy configuration

hi,

i have a client who is using AD SSO with auto proxy configuration from astaro itself everything things seems to be ok till last night or exactly till wednesday evening but saturday morning (week first day) there was problem with internet access... AD SSO was not working it was directing to fallback action that surfing is block.

proxy auto configurtion is
function FindProxyForURL(url, host)

{
if (isInNet(myIpAddress(), "10.0.0.0", "255.255.255.0"))

return "PROXY 10.0.0.3:8080";

else
return "DIRECT";

}
and it has been sending to client by using GPO.. does anything i am missing..

thanks in advance...