Bridge/Repeater for Wireless Networks

I am using Wateen Wimax external device for internet connectivity. This device is connected to my Linksys WRT54g wireless router. In this case, wireless router is just acting as a switch and is not routing at all. Wateen device is acting as a DHCP server also and my wireless router is just providing wireless connectivity to my mobile and laptop. All this setup is installed at first floor and wireless signals drop in the ground floor. Now I have bought a TP-Link Wireless TL-WA501g Access point to use it as a repeater and according to its specs it can bridge/repeat wireless networks. Somehow I am not able to configure it correctly. I tried it a couple of times but it gives its own set of IP addresses to users, however DHCP is disabled on it.

Would you provide your expert advice on this problem?