I've been having the exact same problem. Found this solution at http://weblogs.mozillazine.org/darin...es/005753.html
"Users of Mozilla on Fedora Core 2 may experience unusually long delays in resolving hostnames. This results from the fact that IPv6 is enabled by default in Fedora Core 2. If you do not need IPv6 support (which is most likely the case), then it is advised that you disable it in the kernel. To do this run the following command as root:
echo "alias net-pf-10 off" >> /etc/modprobe.conf
You will need to reboot to have this take effect (or simply unload the ipv6 kernel module)."
This worked for me - internet is flying again.