I just installed a BGN wireless router to replace my sturdy BG router. I used the standard setting for the router.  My Lenovo laptop connected easily. Great!

My problem was that my friend’s macbook couldn’t connect, even if all the passwords, etc. were correct.  Airport actually indicated a connection, but under advanced settings / TCPIP you would see that the Airport was NOT picking up an IP address from the router’s DHCP server.  I was getting a local address on the macbook.  I checked the router, and it indicated the macbook as a DHCP client … so I knew that one was assigned to the macbook.

SOLUTION:  Use a lower channel on the router.

I was originally set to channel 11 on my router.  I set it to 5, and voila! all my open browser screens on the macbook connected!

… mmmm…. I love these simple fixes!

Hope this helps.