Accessing the proxy from internet connects but doesn't browse

[MartinSca]

I have servers with addresses like 159.42.X.X (internet) that need to browse using the proxy.
I have other servers in private addresses that can browse with out problems.
current conf
acl localnet src 0.0.0.0/0
http_access allow localnet
No details appeared in the logs.. nothing at all
if I do a telnet from a regular machine I can se activity, from this servers connects but does nothing and after a minute disconnects.