No ip-masquerade after upgrade 2.2.19 to 2.4.20

[Russ Cook <russcook@flash.net>]

I have a home network of 5 machines running Linux (for me) and
Windows (for wife and son).  I have a masquerading gateway machine
for internet access.  I update this machine rarely, as problems
encountered affect the whole family.

I recently took the plunge and upgraded the kernel on that machine
from 2.2.19 to 2.4.20.  Now, it no longer provides internet access
for the lan.  From the gateway's console, I can access the internet,
so ppp is working.  The machine is accessible from the other computers,
so the eth0 funtions are working.  Can anyone help me troubleshoot this
problem?

In a rare moment of foresight, I kept the previous kernel and labeled
it 'safe' in lilo.conf, so I can still use that kernel, and currently
am.

Thanks much,
   Russ