I have a similar problem, but I'll try what was suggested here. I will not get a chance to for a couple of days, but let me ask some follow up questions.
My situation involves two routers, but router one is a DSL modem/router and router two is a wireless router. Both have DHCP running on them. The wireless is for our lan and the dsl one is for internet connection.
Router one, the DSL modem, defaults to 192.168.254 and router two defaults to 192.168.0.
On the 192.168.0 lan are three computers and two printers - the printers use the ethernet ports on the wireless router while the pc's use the wireless connection. The wireless router has four cable ports and a WAN port.
On router one, there is only the one ethernet port which is supposed to go to a pc. There is also a fon line in. If you are connecting to a hub, there is a crossover ethernet cord to use.
So let me see if I have this straight. Disable the DHCP on the wireless router (# two), cable from router one to router two lan port (1 of 4), but not wan port.
Do I use the crossover cable? Do I change the wireless router's ip to be on the DSL router's subnet - 192.168.254?
Both vendors have told me I need to disable the others dhcp server. Neither has provided a solution that worked.