Network issue - dynamic ips

[T Molnar]

Hi all,
Perhaps someone knows a bit about this and can make some suggestions.

I had a cable connection with 2 static ips running 2 computers off a 
hub coming off the cable modem.
However, I wanted to add a 3rd computer.

So I put a router on the cable modem, set up the address for the router 
with one of my static ip's and
all three computers (tibook os x, 7200 os 9.22, 9500 os 9.2) to 
configure dynamically using dhcp.

Things worked fine for several hours, but now the tibook will lose 
connection off and on, sometimes the 7200.
When this happen in the OS X network panel under network status it 
shows no connection, not even showing that
the built in ethernet is turned off.  There's just nothing in the 
network status box.

Restarting seems to help.

It's the router assigning the dynamic ip, so I am not too sure why 
everyonce in a while the connection will just drop.

Any insight into this? anyone?

cheers and thanks
tim