Check the Belkin's DHCP setup, you must disable the DHCP. The D-Link most likely has DHCP enabled and is issuing addresses to connecting clients. If the Belkin is doing the same, there will be conflict between the two.
Manually issue an address to the Belkin and also Subnet Mask, Gateway and DNS in the LAN settings if you haven't already. The Gateway and DNS addresses must be the IP address ao the D-Link.