Some things to try:
Turn off Short GI and Extra Wireless Protection or WLAN Partition. if you have it. Under Advanced/Advanced Wireless.
Setup DHCP reserved IP addresses for all devices on the router. Setup/Networking
Ensure devices are set to auto obtain an IP address.
Still no luck after trying the above. Turned off Short GI and WLAN Partition was already turned off. All devices connecting to the router are set to auto obtain IP address.
It is a Brother laser printer with its own wired network port. It has worked like a champ with all other wireless and wired routers. Right now I have it setup Cable Modem > D-Link DIR-665 > Devices
Printer is hard wired and works on my networked wired WIN XP machine.
Laptop Mac Lion 10.7.2 works if I turn off the WIFI on the laptop and plug in a network wire. When the laptop is hooked up via WIFI it sees the printer as ready and idle. When I print it then shows up as disconnected.