wried connection problem

I have 2 asus routers, WL-500W and WL-500gP, both use stock fw. I used to connect in this way: cable modem -> 500gP -> 500W -> 2 PCs & usb printer. THese were all wired except 500gP was the gateway & doubled as AP. 500W was only used as a hub with radio off, and static IP for USB print server. THis config had been used for over 3 years and I forgot the detail setting of both. I need this config because I have a wall between the two routers.

Yesterday I swap the two routers trying to use 500W's 11N ability for AP. I can make 500W serve its purpose in the new config. But I couldn't get the 500gP right. I've set it in AP mode (the only mode I can set static IP for print server), disable the radio, same wifi security key as 500W, disable DHCP etc. But my PCs are not getting any IP from the gateway. Can anybody please advise me what settings need to attend for such config?