DHCP is disabled on the WRT54G2 and anything connected wirelessly to it gets its IP from the DHCP server on the Actiontec
Disconnect the Actiontec from the WRT54G2 and enable the DHCP server on the WRT54G2. Try it again.
You should connect the Actiontec to the WRT54 with the internet port of the WRT54 connected to the Actiontec. Enable the DHCP client on the internet port of the WRT54G2.