I had same problem.

My system is external dial-up modem plus ethernet card for home network.

I could connect to my ISP with KPPP but could not access the web, email etc.
Solved problem by booting from Knoppix CD and copy the following files to the HDD install:-

/etc/resolve.conf
/etc/host.conf
/etc/hostname
/etc/hosts
/etc/hosts.allow
/etc/hosts.deny
/etc/network.interfaces.

After rebott, 'net access worked.

trueocker