it might be dns, try accessing a site with ip address, click this
http://64.179.4.146
some dialup setups will require you to put some nameservers in
do you have
/etc/resolv.conf
just get the nameservers from your isp and put them in /etc/resolv.conf
nameserver 68.63.0.5
nameserver 68.63.0.6
search mydomain.com
PEERDNS=yes
in your options file